Overall I think Liszt is easy to play compared to his reputation, and most definitely, how his music sounds. For me, personally, I have not had much difficulty playing Liszt well because, as someone else pointed out, he was a great pianist himself! He wrote it to make sense...so it's easier I think for pianists to play it now. However, I don't think the musical nature should really be brought into this discussion. Everyone is always going on and on about interpreting a piece correctly, but I think worrying about it only makes the problem worse. Now, I'm no wonderful pianist but I haven't been playing for very long either...I know that there are some parts in music that really must be well thought-out, yes, but most of it I think is just playing it with excitement, particularly in Liszt, and that shouldn't be difficult to achieve.
Anyway, I think if we start going on about "well, sure, but how easy is it to play it WELL?!" and so forth, the truth is, we're not going to have a very productive discussion in this topic. Where someone has an easy time playing Chopin musically, or at least to a fair degree (as most of us do..and should...), they might have problems making Bach sound good. So, I think we should just look at it on a technical scale: what things sound technically harder than they are? This is where I think a lot of Liszt's music qualifies. For instance, I just finished listening to Totentanz...Overall, from what I've played from this piece, I'd say it's quite a bit easier than what a beginner might think from listening to it. Same, perhaps, with La Campanella (though, in this piece, I agree that the tempo dictates the difficulty. Try playing it at Cziffra's speed for a challenge!).