It IS fully functional as long as you do what I said a couple of posts back, delete the FM Radio App, HTC_IME and put the ERI file in so you get carrier stats so you dont get the roaming symbol anymore.
System storage using the Firerat MTD of 150 2 gives me 35.44mb free on the 150mb System partition..
This ROM is really growing on me... Some things to consider..
Do NOT use titanium backup to backup and restore the APNs to MIUI, make sure you enter them yourself from scratch.. Also do NOT restore any SMS messages.. It will make your message app FC all the time.. start from scratch with that.. Using Titanium to restore stuff like Angry Birds saves etc is fine, just dont use it for any system stuff, looks like it has some compatibility issues..
Other than that, and the *228 issue (just use *228+) its great... It looks and feels totally different from other Android ROMS which is probably why I am liking it..
Besides, do a nandroid backup and take the plunge...