I have the titanal 2's and I just purchased some freerides. Freerides have a more robust toepiece, and Fritschi claims the rail is stronger too. I can't tell the difference by looking at the rail. The shims appear to be purely cosmetic. They climb excactly the same. They feel tighter than my Titanal 2's, but they are new, so who knows.
Take a good look at the Naxos before you buy. The adjustment teeth for the boot length looks suspect, and I didn't trust the plastic threads for the boot height adjustment. So far I can't find anyone who will report on them. Maybe after a year or two of evolution...