I do think that the optical is more prone to having things go wrong with it and if you bend an optical cable too much it can go bad.
Probably no advantage to using a high dollar recorder for digi-in, but a cheap one can lead to problems (MT 24/96 and MTII lock up problems, etc.). I would not go with the MT unless you are willing to risk losing a possibly important recording every once in a while. Even once is too often.