Rosanna: thanx for the "great pianist" remark; I love you too (virtually speaking
The transcendental etudes vary considerably in the level of difficulty. There are some that are not much different in level of needed virtuosity from Chopin etudes, most notably, TE1, TE3 and TE6. The most difficult ones are TE4, TE5 and TE12, the rest falls in the middle.
From personal experience...
Relevant background info: Despite flattering Rosanna's comment (thanx again!), my talent is quite mediocre (or I would have chosen a pianist career - trust me, I really wanted that when I was about 16); you may be way more talented. On the other hand, I have had considerable training (7 years of formal music school), though restarted piano only 2 years ago after a 12 year gap. Here are my observations re: Liszt's Transcendental Etudes:
TE1 is about as difficult as easier Chopin's etudes (mostly because it does not require much endurance, at under 1 minute); it was relatively easy for me (no Carnegie Hall worthy performances though).
TE6 is a bit more difficult; I've toyed with some of the passages there, but postponed learning it in favor of Chopin's 25/12, which I consider to be about the same in difficulty (they are also about similar technique).
I've also toyed with TE12. This beast of an etude is in a class of itself. Right now I completely fail to achieve anything resembling its proper sound, and I suspect that I may fail completely even after spending years on it. This is the first piano piece that I cannot possibly play on a heavy keyboard (which I generally prefer), and it makes me seriously consider purchasing a piano with lighter and shallower keys (like some of the Playel pianos).
As usual, all disclaimers apply, see my signature