I think it's quite cleverly written, not deeply written, just cleverly. I suppose it belongs to the school of thought and period where you simply wrote variations on themes, you didn't develop them per se (I have to say that I think a lot of the Viennese and post-Viennese theme and variation style pieces are dreadfully dull). In many ways that was Liszt's great innovation - transformation of themes.
I have to disagree ! Mozart and Beethoven variations are anything but dull, and they do a damn sight more with their material than Thalberg does here.
Hmm. I think the Eroica variations are terribly "worthy" (the Diabellis are more exalted) and imo some of the fantasies on operatic themes which predate this era simply don't work very well. There may be more wit in some Mozart and Beethoven, I grant you that - this is essentially just a cornucopia of pianistic devices. As such it is imo a lot better than stuff by the likes of Herz, Pixis (which I've just been looking at), Dohler, and various others of that ilk. I don't even find Alkan's early operatic fantasies/variations very convincing.