1) Try not to ask for rom recommendations. It is only a little less better than asking for the "best" rom...and it also makes you seem a bit lazy. This tablet is a beast, and flashes roms in no time. I can flash and test briefly all of the flo roms listed on XDA in 2 days, tops. And usually, when I try new roms, I touch and go.
2) Just because roms have nightlies, it certainly does not mean that they are any less stable. It is nothing more than the devs pushing put their daily progress. In a nutshell, the devs release nightlies based from their most stable build. Tomorrow's nightly might have better RAM usage than today's nightly, and they allow you to flash instead of waiting days/weeks. It is up to the dev team to make that decision. Go ahead and try using any of the two roms for yourself, and you'll see what I mean. If you run into a problem, simply report it. Don't be afraid of bugs.
3) You really should look into learning more about DPIs. Using one general DPI for the entire system might not give you the best resolution for each app. I use Xposed Framework (along with most of the people here), and I change my DPIs on the fly by putting the App Settings into Sidebar (last app on left of screenshot).
The biggest point of this post is to try them both for yourself. Read the OP in the different threads to see if they have any bugs listed. Most don't.
Phone: HTC EVO 4G LTE
Rooted, Custom Rom & Kernel
Tablet: ASUS Nexus 7.2
Rooted, Stock Rom & Kernel