I would certainly recommend the elipsa, having wrestled with the trade-offs between the two. Listening to Cremona and then listening to elipsa will solve your dilemma. One of the reasons I went with elipsa had to do with room placement. Cremonas need to stand well out from the walls and for best performance their placement in the room is critical. elipsa is less intrusive in the living, walking around space, and less fussy about placement. To be sure, their sound is optimized through careful experimentation, but their sweet spot is wider and deeper.
Take the plunge, your 501s will never be happier.