They also have an option to add your calendar notifications to the lockscreen as well for daily events. I don't have them added there, but it's a nice touch to see what is on your literary next with a quick glance. Cyanogen is really the only ROM I trust and the most professional. I don't agree with all their decisions (though that's kind of typical of any project), but they're more professional than most other projects and have higher standards for gerrit commits they accept.

They have a built in updater for their ROMs since Cyanogen 9 (4.0) so no more having to download from a website. Delta updates may have been merged in recently, but have not had time to stay on top of their changes. Killer feature for me though has always been switching music tracks with the volume buttons (like how Blackberry would do it by hold pressing the volume button). I never knew how much I missed it until trying to run one day without it. It's a pretty trivial thing to add to the AOSP source though (add maybe 50 lines total to a few Java files in the framework base) and wished Google would do it. I can only assume there must be some sort of patent/licensing reason as to why they don't.

You're right about wasted space and stock devices have yet to really find a good way to use it. I don't really like how Google implemented lockscreen widgets in 4.2 if you tried them out yet. They're either full out maximized (by pulling them down and thus no easier than unlocking the device) or they're minimal. Someone will probably mod them to be more customized in the community I would guess. I'm still using 4.1.2 on my Galaxy Nexus just for stability since CM 10.1 (4.2.1) is still in early development.

Random question, but how is the post-jailbreak modding community for iphone? I mean I could look it up, but I'm guessing you have some first hand observations.