The search function is your friend .....
You could always read the 100's of posts on the subject but to paraphrase them here is a potted history (I've owned both so I can comment

):
Twat Suit:
positives are - quality, venting, guarantee, styling (for some). The outer doesn't get heavy if you re-proof it with the correct NicWax stuff to repel water. The inner lining doesn't normally leak, people just don't wear the correct base layers and so they sweat.
negatives are - styling (for some). There is no adjustment so you either buy to fit over winter layers (flappy in the summer) or to fit over summer layers (too tight with winter thermals). You must wear technical layers as otherwise you sweat and feel like it leaks. There is no thermal lining. COST!
Rev'It Cayenne:
positives are - good vfm, adjustable on arms and waist, three leg lengths, thermal as well as waterproof lining (can be used together or seperately), three colour combos so not a 'uniform', styling
negatives are - may not be in the Rukka / twat suit quality level, zips a little flimsy (I've had no issues but they aren't as chunky as the twat suit), no back protector (although one can be bought as an extra), the label isn't as 'designer' as some.
I've had the twat now I'm twatish.
