tgp2 may convert better (i haven't done it in a time). the reason it flopped was not the conversions.. it was the lack of tgp2 traffic. tgp2 owners felt that they couldn't get enough traffic as compared to the traffic that tgp1 owners got..
take this example, if you get 10,000 hits a day to a tgp2 gallery which gets you 1 sale vs.. 50,000 a day to a tgp1 gallery which gets you 2 sales just because you are getting more traffic. which would you do? i'd take the 2 sales any day! sure you would like it to convert better but in the end you want more sales and more $$$
with the lack of tgp2 sites, it's even harder to get traffic.
as for the surfer mentally.. i'm sure they know that tons of free porn exists.. tgp1,tgp2,mgp,linklist sites.. after a while they are all the same! yes they will always look for more free porn. they will look for better and better. from tgp1 -> tgp2 -> mgp. you can't stop it.. every site owner is fighting for there attention by providing more and more free porn.. it may seem that tgp1 is giving away more free porn than tgp2.. but it really isn't.. it's still giving a surfer a SAMPLE.. what you are hoping for is that the surfer eventually gets bored of the samples.. and want to see more of a certain girl.. more or a certain niche.. some 30 minute videos of a particular model.. something that NO tgp can give for free...