Ah, glad to. It's a custom ROM of course, developed by sombionix over at xda. It's been optimized for speed as you might expect and does away with a good amount of the bloatware Samsung was so good to bless us with.
I could hardly expect you to read the whole forum thread...it's over 8000 posts now! There's a fair amount of nonsense on there, but also a good amount of useful information if you can wade through it all.
The theme of Bionix is "black goodness," though there is a download to return to the stock look after flashing the ROM.
It comes already rooted and is installed via ROM Manager, or more specifically ClockwordMod.
Installing the ROM will wipe out all your apps so you need Titanium Backup to back everything up prior to flashing.
There are a few different options for kernels...the stock kernel, JAC's kernel and Kingklick's kernel. The latter two are capable of overclocking the CPU and are also configured to undervolt the CPU, theoretically increasing battery life. I've not noticed a great difference in battery life, but I certainly have seen a huge increase in speed using JAC's kernel in conjunction with a lagfix called Voodoo. Voodoo can be a pain, but it's worth it to me.
You'd likely do well the Bionix 1.8 and Kingklick's kernel. You don't have to overclock if you don't want to. SetCPU, the overclocking app, is available to xda members for free.
There are
some bugs, but by and large the dev has done a pretty amazing job of getting things to work. Personally, I've yet to have any problems. Most of the time the ones who do have problems don't read carefully enough or simply fail to reboot their phones first to see if things clear up.
It's not something to leap into blindly, but I'm confident you're not the type to do such a thing. Some research is in order, but if you pay attention and can follow directions, it's not all that hard. Again, I expect you're fully capable of that.
You already have experience with Odin, and this is very good knowledge to have. Unless something truly catastrophic occurs, you can always use Odin to get back to stock.
[ROM] Bionix 1.8 - Complete JI6 Build - Can't believe it's not butter *10/12/10* - xda-developers
Take a look. If you find yourself interested, let me know and I'll help as much as I can. It really is a lot of fun to play with these things. And I guarantee that my Vibrant can make your Vibrant cry!