An unholy TIE-ROM hybrid, with a plethora of other mods, and some of my own tweaks (via TES4Edit and now TESCS as well) to round it out. Not to mention Wrye Bash and all that it brings to the table, of course!

So yes, I use overhauls.

I use FCOM

No overhauls. I am considering trying http://www.tesnexus.com/downloads/file.php?id=37217. It's a very uncomplicated and light overhaul that doesn't change all kinds of things and wouldn't require me to download special versions of most mods. I admit I really do not mind the vanilla system overall. I don't particularly mind being the "center of the universe." I've been tempted by overhauls but the problem for me is, all overhauls are someone else's idea of a perfect game and the more complicated they are, the more likely I am to disagree with some of it. I am an a la carte kind of person with quirky preferences. TIE or Frans might possibly be ones I may try eventually, but right now I'm pretty happy with my game without.

Long term OOO user here (since 1.33 came out). I've experimented with OOO+MMM, TIE and ROM, but allways come back to straight OOO. It does just enough for my tastes,along with realistic fatigue, Duke Patrick's combat archery, LAME and Phitt's Phighting Phixes.

Used OOO + MMM for a long time, then Fran + MMM, then TIE, and now FCOM for the last year or so.