I just received these bibs yesterday and immediately tried them on for size and they felt incredible! I just returned from my evening 20 mile ride and OMG these are hands down the absolute best bibs ever!! After 10 years of riding I've tried about every brand on the market and have always considered Assos and Castelli the cutting edge to which every other brand is measured. I'm only 5'10" but weigh over 200lbs with a 47" chest and large thighs, 23" above the knee and 28" at the crotch. At least for me the 3XL are the perfect size, from the long legs without a gripper but a nice wide soft hem, to the straps that are soft, wide, flexible, and extremely comfortable. The waist is also a perfect cut; not too low, and not so high that you have to bend over to relieve yourself. The chamois doesn't feel thick but it must be the perfect cut because I can't tell where it ends and the legs begin.
I rarely if ever write a review about a product that I've purchased but I read almost every other review from others and yes, they do actually disappear when you put these on. I still have them on because frankly they are too damn comfy to take off but I prob should shower before I hit the sack.
I can't wait for my other 2 pairs that I just ordered and I'm starting to think about listing the others on ebay soon.