Ok, it seems some other people have been experiencing this, so just looking to get some input into the following...
So, for the most part, 1.5 has been amazing. But twice now, the phone has literally slowed to a crawl. This usually happened after listening to music for some time. The screen wouldn't turn back on, and when it finally did, nothing was responsive. The first time it did this, I was running the Slayher kernel. Flashed Chevy's 1.2Ghz ULV kernel hoping to resolve the problem (this was after I had tried disabling CompCache first). After running Chevys kernel for 2 days, it happened again today on my way home from work. Same exact circumstances.
Here's where it gets weirder.. while I was still running the Slayher kernel, I had the Smoked theme installed (stay with me here!). Now, I'm not necessarily blaming the theme, but there would points where LP would just crawl. I had switched to ADW, which magically seemed to fix the problem, only for it to slow to a crawl as mentioned earlier. I tried to remove LP from /system/app, reboot and then reinstall from the Market hoping it would fix the issue. Seemed to work initially, and then I used the fix posted by bemenaker to get rid of the redraw lag. Again, it seemed to work initially. But this crippling, slow down to a crawl situation on my phone was very odd.
So, after today's repeat crippling performance, I decided that enough was enough. I tried to think about how my phone was before this stuff was happening and realized that all was good before applying the Smoked theme. I decided to use a Clockwork backup I had made after installing stock LFY1.5 + Slayher 1.2 Ghz LV kernel. I wiped data/cache and wiped the boot and system partitions in Clockwork, then restored that backup. Since restoring and flashing Chevys 1.2Ghz ULV, all has been great..
Will update this based on the next 48 hours to see if this was the real issue or not.
Even with this little hiccup, root is worth it, haha!
Primary Device: Samsung Galaxy Note 2 (SCH-i605)
Other Devices Owned: iPhone 5S, iPad, Nexus 7