1.1-1.2 was just great, relatively stock rom (look at the bottom of post 2 I keep the previous working versions listed there for download as well as options). Sorry, I don't remember the specifics on the differences, it may have just been a matter of getting it working right, but you would want the last V2 for that regardless. This has no issues with the new market, but may take a bit to get the update.
1.3 and 1.5 are essentially the same thing except 1.3 uses Amend scripting to install, which means older recoveries like Xionia. 1.5 uses Edify coding so it works on most recoveries thus allowing you to switch back and forth with IHO Gingerbread roms without changing recoveries. 1.3 I tried to incorporate the new market, sometimes it works, sometimes it doesn't. 1.5 I skipped that, however there is a bug that limits you to the stock storage space. The big change on these was they both have the time without signal fix, as well as the powerbutton menu to boot into recovery. They do sometimes have issues with the new market though, but the old one works fine.
Since you haven't done it yet, wait for the new release, which will be labeled 1.5f or more as it will be the one to use as it will work on most any recovery, and will have the memory issue corrected. I should have it done this weekend.
A note on the new market.
Google changed the security system on the Market while 1.3 was being made. The problem is that to get the power button menu and TWS fix you have to change a few files and re-sign them. The new Market security doesn't like the fact that now the signings do not match. This creates an issue in that to keep moddding Froyo, we either change how we build (not easy), stop modding those files, or rebuild the market apk on each minor update (which opens up another can of worms). This is just another reason why I'm working on an IHO based Gingerbread rom, to get away from this problem.