The main things I want from a phone are stability (critical), then flexibility and performance. Stability and reliability really are important.
The ROMs I'm considering are:
Pros: Based on TouchWiz, so has all the right drivers. Samsung bloat presumably removed, though not sure. A few apps and extra behaviour introduced.
Cons: Less well known/trustworthy. Touchwiz keeps apps seperated into normal and downloaded, downloaded isn't sorted - that's just annoying.
XDA Link: http://forum.xda-developers.com/showthread.php?t=2555569
Pros: Stock, well known and trusted, frequent updates. Should be fast, flexible, and reliable.
Cons: Updates may have to be applied manually (no problem). Unsure whether all the correct drivers are present for all the hardware, for the proper Google Edition phone Samsung builds it with the drivers. Suspect it's done fine.
XDA Link: http://forum.xda-developers.com/showthread.php?t=2341026
Pros: Well known, trusted, supported, tested. It's almost a commercial distribution. Based on ASOP so should be pretty clean.
Cons: on my old TF101 tablet it rebooted occasionally, though a friend of mine says it was great on his S2 and battery life was better than stock firmware
XDA link: http://forum.xda-developers.com/showthread.php?t=2521384
I'd appreciate hearing from people who've tried any of these ROMs on their i9505, or who know about them. Also interested in how it applies to Telecom phones, eg LTE support, roaming.