Brandon, I can tell you CM10 on the Nexus is pretty sweet.
I've never really done nightlys before, and I think I'm going to start getting one every 3 days or so.
Installed Nova and smooth as silk, although I'm not that worried about stutter. Battery life is improving, just need to get the right kernel set up.
Picked Franco's and set up my own power profile. Standby is fantastic, although that screen still chews up battery.
Tried AOKP, but honestly don't need all the options it offers, and it's unsupported officially. Noticed signal took awhile to lock as well as some issues with clock force closing. CM hasn't given me any issues so far.
Biggest issue I've had are apps that have been a little slow to adopt the JB sdk and be 100%. Some have minor issues, others just crash. BeWeather finally updated and it's much quicker. Have been tempted by other weather apps but have stayed the course. Sentimental reasons actually.
I had a hard time changing the dang CLOCK on my HTC One S lockscreen! What the H E double hockey sticks are you guys talkin' about?!
Nightlies are basically improved rom every night. That's oversimplifying it a bit...
When new code is merged into the existing containing new features or bug fixes (or improvements) then a "nightly" is generated. Some developers wait a week and release any improvements/enhancements. Others will go longer or slightly shorter, but in the end you get what they put out as a new download.
Example, CM merged their launcher in the build the night before last. So when I downloaded Euroskank (fitsugly kang of cm) it was now included the next day (maybe a day lag). Another example would be the notification toggles, which were not in one build but showed up the next day. In a nutshell nightlies just give you the improvements quicker. Sometimes there's a hiccup, and the improvements don't always work...such is the life of flashing.
The kang I'm running is rock solid. Only thing that hasn't worked for me is the storage setting in "settings". No biggie since I've never used it on any device or any rom before.
Kernels are (and I'm not quoting anyone...just my thumbnail) the core of Android as it is Linux. Basically the kernel will allow you to tweak settings like the clock speed (overclocking, underclocking, controlling voltage to the cpu/grafix chip), control and change color settings (think what you can do with a monitor), change cpu governor (how quickly it ramps up to full speed and when), set a power mode (min/max speeds and when), increase sound volume (useful on the Nexus), Thermal throttle (if it get's hot...shut er down) and others. Usually varies by kernel. I run Franco and use the app from the market to control it. It's possible to change settings through editing a file manually, but I'm lazy and like to be able to just change on the fly.
Roger all this will come to you. You're used to the closed ecosystem of Apple (jailbreak included, cause even jailbroken you don't have all the options you will on Android). With that One S you can root, allowing access to the entire file system and increase performance if you choose. Beautiful thing is no matter what choice you make the device will be your own.
If you get tired of Sense (which isn't hard to do) you can experiment with the ICS/JB launcher by downloading Nova or Apex from the market for free. The free versions will give you a taste of stock, although not 100%. They will also give you far more control over your homescreens/widgets than stock sense will.
H E double hockey sticks...always think of Radar on M*A*S*H when I see that. Was the first time I ever heard the phrase and was watching with my dad..... good times....good times.