Speakers for $600.

I'm looking at upgrading my Wharfedale Diamond 9.6s. They just aren't exciting enough nor do they image well enough for me. I'm looking for a used monitor in the $600 price range that would be well suited for jazz and rock. I don't require too much bottom end. The speakers will be powered by an Onix SP3 MKII integrated amplifier. So far I'm looking at the Triangle Stella ESs. These seem to be highly reviewed and meet my requirements. Any reason I should go with something different?