Not sure where to report issues and overall experience, so I'm doing this here.
System: july 14 nightly, installed on SD card (8 GB, class 4, the one who came with the phone). Froyo kernel (is it even available for /gb kernel?)
Boot took a very long time. It didn't give me a bootloop suspect or anything like this, just that the boot animation was running slowly as hell.
UX is, at least, pleasant. Even though it's running from the SD, it's fast and good enough for daily use, in this matter. Transitions are smooth, a few lags are noticeable, but I'm way more inclined to blame my SD than the ROM itself. There are no toggles on the notifications pane, nor power off menu yet, I'm assuming they're simply not implemented on the framework yet. Overall use seems just right, great considering we're dealing with a 4 days old build.
Most functions work out of the box: data, wifi, touchscreen, sensors (accelerometer and ambient light - didn't test proximity). No sound, as stated. Didn't test calls. Also, since I'm running it from the SD, didn't test mass storage. Camera is ok, uploaded a couple of pics taken with it.
I'm having troubles with my battery (retaining about 15% of its original capacity, only - percentage gaps happen all the time), but a new one is coming today. Maybe I update this post, later, with batt life experience, won't assure this since IDK if I'm able to run a full day without my apps.
Titanium backup wasn't able to get root permissions, nor wasn't Screenshot by Kastor Soft (I were able to take screen caps using the default JB method), although other apps were. Can't tell if it's because I'm on a virtual system or a build issue.
Market's working fine, but many apps aren't installed, giving me a "Couldn't install on USB storage or SD card" error after downloading. I also assume that has something to do with running JB from the SD card.
Google Now has not been implemented in CM10 yet, so there's nothing to say about it. If one taps the search bar at the home screen, it even shows some sort of introduction for GN, but, as soon as you opt in, it crashes.
Now, my favorite part: benchmarks. First of all, I wasn't able to get NenaMark to install, from market it gave me the aforementioned error, and couldn't restore my titanium backup for it, so I'll pass this one.
Linpack (single-threaded): 16.116 MFlops (around 15-16 on CM9)
Quadrant: 1355 (around 1800-1900 on CM9)
BenchmarkPi: 1499 ms (1400-1500 on CM9)
CFBench: 3025,1029,1827 (3356, 1074, 1986 on CM9)
Browsermark: 59529 (45325 on CM9).