Im no pump expert but my Quaha and my Silvia both have Ulka pumps and Ive never had a problem with either of them which anecdotally appears to be the experience of many. Alan Frew concurs. Not sure why theyre supposed to be so bad?
The other advantage with rotary is the lack of noise factor, but personally I doubt its worth the money unless youve got a pillow full of the stuff ::) (in which case lets be friends! ;D)