My experience of Carbon ROM has been short and a mixture of good and bad. Good in that there were some very nice features, but bad, in that the whole ROM seemed to not be too responsive. Less of a problem with Carbon ROM compared to the last one I tried, but, still, definitely noticeable.
I’ve taken a quick look at XDA and found a couple of other ROMs available, so I’m going to download them and give each one a go. 4Ext really helps with the backups.