For that price, I would say definitely worth it, especially if the phone is in good condition. My Gio was bought in the release too and has survived many drops etc. Just get one of those cheap TPU silicon protective covers and you're good.
I have not tried CM11 yet, I heard there is still some problems with camera and performance, so I have have stayed on mardon's Cyanogenmod 10.1 and I think it is very usable on this phone. It's definitely worth a try at least!
I wouldn't use anything above CM7.2 though because there's no RAM.
Battery life on CM7.2 will be better, but other than that, CM10.1 should perform equally with no massive problems on this phone despite the low amount of RAM.