hey OLDJACKBOB I noticed your using vUV2 691 with jit enabled hows that working out for you what's your linpack score? I'm thinking about trying vUV2 701 with jit enabled...also do u know if urushiols v4 kernel is undvolted our not?
You happened to ask that at the perfect time, because I finally got my first random reboot, with multiple looping reboots, this afternoon.
I was recording my road biking route with Maverick, and was also listening to the stock mp3 player. I had enabled both apps, then blanked the screen and dropped my phone into my jersey back pocket and took off on my ride. NOTE: Lest anyone go ballistic about the dangers of listening to tunes while riding a bicycle, understand that I was riding on a no-motor-vehicle route, so it was perfectly safe.
When my ride was finished, I retreived my phone from my pocket to stop the GPS recorder, but as soon as I unlocked the screen the phone went into the boot loop.
I pulled the battery and booted into the recovery screen and flashed the disable-jit zip, and have been running without incident ever since.
So apparently something went unstable during screen-blanked mode, with multiple apps still running in the background.
Another thing I decided to do is to flash the v4_691 kernel, because I've been thinking for awhile that maybe the GPS module doesn't like undervolting.
My linpack scores while jit'd were in the 3.8 range, with the cpu clock running at 576 mhz (I don't really feel comfortable cranking the cpu speed very much over the factory 528 mhz setting).
My linpack scores now that I'm running with jit disabled are in the 2.8 range.
So I can definitely vouch for the fact that jit does make a big difference, all other things being equal. Unfortunately, I'm not willing to deal with the random reboot issue, even though it only happened once over several days of steady phone use.
To answer your question about whether the v4 kernel is undervolted, no it isn't...it runs at the full voltage that the factory ROM came programmed for.