I finally decided on a brand of STP/packer and was recommended peecock. After the iffy reviews regarding freetom, peecock is the winner. Sad, I really liked their uncut packer (I prefer that look personally).

So now I gotta decide on which one! My friend who has one says its awesome, but peeing is a learning process. He has a Gen2(s I think). I saw that and like it but am curious as to why the shirts pulled down like that. Can it not stay down on it's own?

Anyway, I guess I'm trying to ask what the difference is and which one might be better. I am a bit paranoid about skin tone as I am not exactly a "dark chocolate" but I'm not light either. I'm a middle, which packer/stp companies seem to forget about. Since it's a bit darker down there it's hard finding one for a middle toned guy that's a little darker to match.

I'm also very nervous with size. I'm 5'6 and skinny, so size is a problem. I was thinking of the 3.75, but which gen is a concern.

I really just want to know the differences between the gens, especially 2, 2s, 3, and 3s. I was thinking 2s or 3, but not until I know the difference.

I've used both, quite contently. Currently using the gen3 pretty much accident free (unless I'm wearing tight pants or really have to pee).

The biggest differences:
-material: gen2 is far softer and floppier than gen3, which is stiffer. Balls on both are pretty dense and don't mash in pants or underwear.
-shape: gen3 is more realistic, though on both the balls are too small for my liking
-size: the 3.75 gen3 is bigger both in length and in girth than the 4 gen2. With your height I'd definitely go for the smallest one. The top "flap" of the gen3 is thicker and sturdier and will show through thin underwear or speedos.
-ease of use: maybe it's because i finally figured out how to use it properly, but the gen3 is a little easier to use, especially with a harness to put it in place. I tended to put it too far backwards, trying to pee in the shaft directly, but that doesn't work. For me anyway
-color: I'm caucasian so it might be different for you, but I feel the color is more natural in the newer one. Though it's still nowhere near the RM or EZP (with paint job). The peecock paint will come off in a matter of days.

If I had to replace mine, i'd go for the gen3 again. It has its issues, but it works for me quite well, even without a harness. If I left something out, feel free to ask.

I don't really know what you mean by 'flap'. Can you explain that?

The bit that sticks out above the shaft at the base, that will rest on your pubic mound.