I recently posted a similar response on a different thread, but...
TnR is much easier to do than TORN. The only potentially ''harder" part would be making the gimmick. If you ever performed or owned Box Monster you would know what kind of thing I mean. The trick is easy, but making the gimmick can be hard (although i have not made it yet, the gimmick looks a lot easier to make in TnR than in Box Monster - although thats kind of irrelevant).
TnR looks much less angle sensetive. TORN is a great trick, but after performing it, TnR looks like it would be a lot less "risky" of a trick. In TORN, those of you who own the trick might agree, if your fingers make a wrong slip you could easily ruin the whole trick. TnR is much harder to mess up because the gimmick does most of the work for you.
TORN is a great trick that can use ANY card a spectator chooses and it can be signed. It is also "more impromptu", if you will, because you need no constructed gimmick. TnR, however, seems much cleaner, less angle sensetive, and is easier to do. You can destroy any card, but if you do the transformation, that new, transformed card can't exactly be "random".
TnR requires a gimmick, and if you hand out the card at the end, it is basically impossible to do it with a signed card. Besides that, I think it is a better trick than TORN. But as far as difficulty in performance, I can't see any way TORN is easier except for the way you hand the card out for examination at the end.