[Xoom Q&A, Help & Troubleshooting] sonophilos:
I wanted to post this somewhere besides the short, dead-end thread about someone else's struggle with apps crashing under EOS4.

This is not exactly a question nor an answer, just information that I really hope reaches the devs who can do something about it.

In this order:

Wiped /data, /cache, and the Dalvik cache via CWM Touch Recovery.

Flashed the 'stock rooted' JB 4.1.2 to get root, something that was missing before. I don't honestly know if it'll help these issues, but it seemed relevant that I hadn't done that yet. Worth noting, the stock rooted ROM has the absolute smoothest launcher/desktop/app drawer animations I've seen, even over stock.

Wiped /data, /cache, and the Dalvik cache via CWM Touch Recovery. (Always, between all flashes.)

Flashed the lastest EOS nightly (20130126-174), followed by the latest Gapps package (20130105). Launcher/desktop/app drawer lag was back, and my earlier mentioned SEVERE audio lag (almost half a second) was back, on the keyboard and in apps.

Nova Launcher with 'Fast/Fast/Jelly Bean' animation settings and all the animation settings in Dev Options set to 0.5x was, and remains, the best-looking solution to the launcher lag. App drawer still has a slight, but noticeable, lag, even with only stock apps inside. Switcher lags, sometimes severely, even when entering or exiting a less intensive app like Google Play Music.

This audio lag, though: It appears to be isolated to EOS's updated Tiamat kernel, as it was fixed (as mentioned earlier) by replacing it with the latest from CM10.1. This fixes the audio lag and slightly alleviates the notification bar pulldown lag, but the launcher/desktop/app drawer still needed Nova to seem close to 'butter' again. This also disables OC, the kernel doesn't support it but EOS's settings will still 'let' you, minus the 'lagfree' governor showing up; the only noticeable effect is about 100MB less available RAM at all times, and choppiness in places as a result.

Mentioned earlier, but the audio and video lag I tested BEFORE I started messing with settings like OC; even a brand-spankin'-new flash of this ROM suffers from it. Mentioned this too, I was using Jetpack Joyride to test, because its sound effects are very punctual. Tried some other apps, they suffer the same lag but I guess it isn't as noticeable. (Fruit Ninja you can hear the fruit being tossed AFTER you see it.) No messing about with the settings seemed to alleviate it, which is why I tried the kernel swap.

So basically where I'm at now is either stock-rooted 4.1.2 that looks and sounds gorgeous, but is feature-barren, or EOS's 4.2.1 that technically runs faster, but looks choppy and awkward and sounds about a half second off at all times, or EOS + CM10's kernel, that splits the difference, still suffering the animation lag and the lack of OC, but with OK audio. After five days of messing with this on 173, and today's struggle on 174, I'm about ready to give up on being 'satisfied' with EOS. I really hope this lengthy post reaches someone who can do something about it, since I am not enabled to post in development forums and cannot privately message anyone just yet.

EDIT: The 'stock rooted' update is 4.1.2, not 4.1.1 as I had posted previously. This seemed like kind of an important oversight.