Mike Newberrywrote a review of Castelli Diluvio Gloves on November 14, 2014
Familiarity: I've used it several times
Neoprene is great. I used to surf and the function of the product, as I understand it, is once I got in the water...the neoprene worked to use my body temp to warm the water between me and the suit.
So, these gloves are great but....for me, only great for a short time (like a CX race). Starting out warm but soon sweaty isn't warm....for long. Don't get me wrong, I like these gloves and use them for my intended purpose...Cross Racing! 40 mins/5 laps is just long enough to fend off wet/cold but any longer, for me, means sweaty hands/cold hands. I don't intend to use these for "long" rides.
Sizing, I have a size 8 glove so the smalls fit great. The fingers are curved just perfect. The cuff isn't too long and it fits tight around my wrist. The gloves are made well, IMHO...stitching is burly. The graphics are cool but I don't expect them to last long due to repeated off and on. I'm hoping they last a couple of seasons but it depends, like everything, how well I take care of them/use them.
All in all, a pretty decent glove for wet/cold riding.