We feel the Alpinestars GP Pro V2 Race Suit runs one size large as compared to the other Current Alpinestars Suits as well as most suits on the market today. At 5' 11" 200lbs with a 32-33 in waist I wear a size 54 Euro / 44 US with an excellent fit with or without adding the Tech-Air Race Airbag System. (This is one size smaller than my GP Tech V2 Race Suit) The airbag does take up a little space for sure but the stretch panels on this suit compensate for it easily. When wearing the suit without the airbag system install in it the mobility improves to a level exceeding expectations allowing it to move like a second skin. - Brian Van
The Alpinestars GP Pro V2 Race Suit is an Excellent Race Suit at the $1,299.00 price point, an solid option whether you intend to add the Tech-Air Race Airbag System or not. All the stretch panels built into this suit to accommodate the Tech-Air System allow it to conform to your individual shape more than suits with less stretch will which results in a personalized fit that makes it easier to move around in. The armor in the suit is top shelf, not just an afterthought.
This race suit will deliver the performance and protection needed for any level of motorcycle racing, track day riding or street riding.
Fully CE certified riding garment to CE – Category II prEN17092 draft standards – AAA class. CE Certified protectors are found in the shoulders, elbows and knee/shins. PE padding is used in the upper arms, torso and coccyx (Alpinestars Nucleon chest and back protection available as upgrade).
This suit is Tech-Air Race Compatible, it is sold separately and not included with the purchase of the suit.
The Alpinestars GP Pro V2 Race Suit Tech-Air Race Compatible is a product we believe in and support with our STG Factory Ride Guarantee. This item includes FREE Shipping for Exchanges and enchanced product support from Team STG. Offer available for US Domestic Orders only. 
1. GP Pro V2 Suit with airbag
I'm 5'7", 150lbs athletic build. The size 38 fits me in a good tight "race fit". The 40 is a comfort fit, but I've got some extra material. I bought 1 size smaller than normal for this suit. I fit a size 40 for the Missile, GP Pro v1, and Spidi Warrior wind Pro. I definitely could not pull off a 38 in the Missile or GP Pro, so consider trying one size down.
For the v2: It is definitely made for the tucked race position. Brian's review is spot on. I have a little bit of butt sag, but everything fits in place well. The arms are slightly long (they come down to the wrist), and the calves are tight when first putting it on (I normally never have calf issues).
My only criticism is that the thigh/hip armor could be a little bigger.
