I dislike conductors that drag the music in Fidelio. "Lack of drama" is right. This isn't Bruckner & therefore the music shouldn't sound like post-romanticism, should it? For example, by the time of his DG recording, Karl Bohm had slowed down in Fidelio (& almost everything else, except possibly Wagner), yet his earlier 1955 Fidelio is surprisingly dynamic & vital, which shows that at one point Bohm was a very good opera conductor. Karajan & Klemperer are too slow for me, as well. Granted, you may find great singers on these recordings, but if the music isn't lithe & nimble enough, it tends to ruin the whole opera as far as I'm concerned.
Therefore, my favorite recordings of Fidelio are (1) a very underrated one, in my opinion, from Kurt Masur & the Rundfunkchor and Gewandhaus orchestra of Leipzig, originally released by Eurodisc in the 1980s--an early digital recording (now reissued by Sony at a super bargain price--$6-7), and (2) among older recordings, Ferenc Fricsay's DG recording with the Bavarian State Opera Choir & Orchestra.
Bernstein can be dynamic too.
Among current conductors that I think are sometimes excellent in Beethoven, I see Bernard Haitink has recorded Fidelio with the Staatskapelle Dresden (for Phillips), though surprisingly, I don't know that recording, and I'd definitely pay to see John Nelson conduct the opera. (If I'm not mistaken, didn't Nelson conduct a live production of Leonore that received glowing reviews?; plus, his Beethoven 8th is one of the best I've heard.) Similarly, it would be interesting to hear one of the original instrument conductors such as John Eliot Gardiner or Jos van Immerseel conduct this music & potentially blow the cobwebs away--especially Immerseel, whose Beethoven 7th--with its authentic valveless horns (whose sounds Beethoven would have recognized)--is one of the most wonderful recordings of that symphony I've heard (though the rest of Immerseel's set wasn't always to my liking).
https://www.amazon.com/Beethoven-Fi...&qid=1511907552&sr=1-2&keywords=fidelio+masur