Was using the 4/09 build and now on 4/11. Both builds have been very stable for me with no issues except data speed and GPS lock speed. It seems since switching to these roms from stock, my data speeds have been a lot slower. I tried loading a different modem (CL5) but it made matters worse. Tried another APN...nope.
So I flashed back to the original modem and its getting me by but its about half the speed I was getting before with the stock rom. For reference, I was getting 3 - 7 Mbps down consistently before flashing CM9...now I am always 1/1.5 - 3.5 Mbps down. Pings were roughly the same between the roms although sometimes I would get insanely high pings with the CL5 modem.
With regards to GPS data lock, the lock speed was much faster in the stock rom. Also, sometimes it fails to retrieve my location with CM9?
Regarding stability and smoothness, this is a beautiful rom!! I encourage those on the fence to try it out. Even though it is a nightly build...it is very usable as a daily driver.
Oh, 1 request pleeeease...Enable Facebook account syncing so we can get our contacts pics from FB!!!
I noticed that CM9 is the build.prop is missing some of the modem enhancements from CM7.
I don't know if its necessary but I always add this to build.prop:
ro.ril.hsxpa=2
ro.ril.hsupa.category=6
ro.ril.hsdpa.category=21
ro.ril.gprsclass=12
ro.ril.enable.dtm=1
Sent from SGH-I777 / CM9 via XDA Premium