I have a Idea (ZTE) Blade it's a gen2 256 MB RAM device. Currently running cm-7-20130101-NIGHTLY with 256 MB Swap enabled on Class 10 card.
This ROM is probably as good as it can get, and there are 2 newer CM versions out there, so I guess the development on CM7 has halted for a while now. My suggestion is to use Konstat's CM10.1 for Blade, it's just smoother and overall much better than CM7.
I have asked same question in CM 9 thread and they said with 256 MB RAM it is better to stick to GB 2.3.7.
Would you still recommend going for Konstat's CM10.1 for Blade?