Franz has some steady, solid points; Thill is resourceful and unique, as usual. I'd agree with Woodduck that there isn't much POETRY in either, but maybe the vocal writing doesn't allow for much. ... Volker, from 1927 or Bayreuth/1936 is very, darn GOOD, and thanks to Barbebleu for the Gedda version! Well, if you want BOTH strength and exceptional vocalism, plus a bit of poetry, one need go no further than the surpassing Melchior, especially 1943 (Met, w/Leinsdorf).