I got these shoes for christmas in a 38.5, I sized half a size down for performance! While the break in period was gnarly I love these shoes and how well they preform, they are stiff in the toe and arch making sure I can really dig my toe in on small holds and so i can get maximum smear power. I will never switch shoes after experiencing the booster s.

Semi-aggressive shoe that is actually pretty comfortable to wear! I think this is due to the flexible mid sole. I normally wear a women's size 8 in street shoe sizing, and got the 39.0. This fits my toes like a dream, but the heel pocket is a little baggy on the sides (too wide). I wish they made these in a women's last, so I am dealing with the non-perfect fit. I couldn't size down without getting a ton of hotspots at the front of my foot.

Otherwise, shoe performs well, good feel on small edges. But, since they are a bit more flexible, it requires stronger feet than, say, Muiras.

purchased the same size as the scarpa instinct vs sz40 and felt a little smaller, although after breaking in they're comfortable enough to stand in for 10-15 minutes and sport climb in without sacrificing enough stretch to compromise the shoes ability to heel hook. For whatever reason i don't seem to see these at the crag as much as other scarpa shoes, (instinct, drago)but these truly are an exceptional shoe with a soft arch for flexibility but a stiffer forefoot that assists with edging. I wore 5.10 dragons for years and have switched to these for hard bouldering, they're slightly stiffer in the forefoot but the extra stiffness is beneficial on small edges so the advantage between the two is a toss up. From what i've noticed they're similar to the new popular la sportiva skwama but the booster s has an additional strap for stability. A 5 star product.

Climber Description:
6 years of experience Bouldering and Sport.
Red Point V6; Climb V7- V8 regularly/ lead 5.12.
High arches, long toes, SHALLOW HEEL

I loved the toe on this shoe I could really feel the rock due to the sensitivity. However when I need the shoe for heel hooks, it had a tendency to pull off of my foot. Keep in mind I wear a regular size 10 and bought a 9.0. For the first two weeks my big toe was purple after thirty minutes. Another words the shoe was as tight as my foot would allow.

This brings me to the break in process, the shoes break in well and were comfortable typically after 15 minutes of stretching and the first 10 minutes of warm up. I could climb comfortably on the smallest of jibs in 20 minutes. After a month I could climb after 10 minutes. It has now been 4 months and the shoes have stretched to the point that the toe box is too wide (allowing toes to slide in shoe) and I can not press off of small jibs.

The rubber is great, I don't think its the stickiest I've climbed with but it was definitely a competitor.

Velcro is durable and lasts, no problem.

Ultimately I have to buy something different because I need to have a heel hook I can rely on. But I don't fault the shoes I fault my tiny, flat heels.

Side note: I know some really powerful climbers who swear by these shoes and I understand why.

This was my first pair of Scarpa climbing shoes and I was definitely impressed by what they had to offer. The shoes themselves are super sensitive, allowing you to feel what you're standing on and they're aggressive enough to keep you on the edge when you're deep in a cave. They do run slightly large though where I sized down from a 44.0 in La Sportiva Futuras and in other Scarpa shoes that I tried on, to a 43.5. Overall, these are my favorite sport climbing shoe that I have ever worn and I will definitely be coming back for more!

I got to demo these shoes first and went up a size or two then they fit snug but climbed amazingly better than my more comfortable beginner shoes. These are really good for tiny foot holds. They stretch in a little bit and become more comfortable after a few climbs

Bought it for steep bouldering but turns out they shine on smears (smooth sandstone), tiny granite crystals (Buttermilks) etc. The shoe is very sensitive - i can feel tiniest credit card features - and very flexible - allows to stand fully extended on these features. The only bad is the baggy heel but i have narrow heel that fits in Dragons. The toe box is relatively wide (wider than Dragons/Pythons) which allows for great smearing.
Size comparison - i own Dragons 7.5 (very tight fit) and Pythons 37.5 (ok fit). Bought these in 39.5 - comfortable fit for all day bouldering/smearing

Awesome shoe that I use for bouldering and sport climbing, actually it is the only pair I have right now besides a pair of moccasyms for cracks. It is very sensitive and flexible with only a half sole. It is basically softer version of the boostic. It is pretty comfortable out of the box and breaks in very nicely. Scarpa is the only make that works for my wider feet. So if you want a high performance sensitive and precise shoe for wide or narrow feet, this is it.

Seemed to wear out sorta fast due to delam on the toe of one shoe. sensitivity and precision are top notch. The heel would probably be pretty good but they stretched out too much for me to know. They stretched a 1/2 size more than my vapors did. I suggest buying a half size down from your normal scarpa size.
Other shoes I wear:
Scarpa vapor V 42.5
Scarpa techno X 42.5
La Sportiva Solution 41
I got a 42.5 in the Booster S and should have got a half size smaller.

Hey guys just got this shoe little bit ago and it's such an amazing shoe. I do a lot of bouldering and wanted to get a more aggressive shoe and chose this one. Glad I did! I had the five ten Moccasyms before and they worked well but nothing like how this shoe performs. I was so confused on what size to get and ended up going from a normal everyday shoe of a 9 to these rock climbing shoes of a size 8. The size 8 (41) is real nice and snug on my foot and pretty tight. If you are a extremist on downsizing I am sure you could go down even further. Definitely would recommend this shoe is worth the money!

These are my new favorite climbing shoes. They are remarkably comfortable for how aggressive they are, and fit my foot like a glove. In my opinion, with the Booster S, Scarpa have found the perfect meeting place between power and sensitivity. I really like how well I am able to feel my footing with these shoes, and think that the psychological reassurance gained from that feel actually more than makes up for any physical loss in power resulting from decreased stiffness. These shoes are definitely very at home on the steeps, although I've enjoyed them on everything between that and mellow slab.

For reference: I size these one half-size smaller than my Boostics.

Highly recommend!

Awesome shoe for bouldering, sport and indoor. Here is a more thorough review I did. http://www.montanabouldering.com/2015/05/the-steep-climbing-weapon-scarpa.html

This is easily the most sensitive shoe i've ever worn. It performs exceptionally well in steeper terrain, and allows your toes and feet to literally "feel" the rock.

I found it was really easy to find ideal foot positioning on holds, be able to turn or maneuver my purchase and adjust my body positioning. It has made moves that I thought were impossible into the realm of possibility. Im all about that sensitivity when it comes to steeper climbing, and dropknees in these bad boys is like a sensory overload.

They run a little bit on the small size, so half size up may be ideal unless you like that super tight fit or like punishing yourself.