mxbum, who has heard the Emeralds and the Ascends side by side, and cschang, who owns the Ascend CBM-170s and CMT-340s and is currently demoing a pair of ACI Sapphires, may be more suited to engage in the Emeralds and Ascends debate.
I do, however, own the CBM-170s and had compared them to the Energy C-3s during my trial period and can weigh in on that matter. The Energy Connoisseur C-3s are IMO very good speakers in their price range and possess qualities of speakers much more expensive.
While I can see where some reviewers see similarities between the Ascends' and the Energy's sound, particularly the very accurate, uncolored presentation of sound, the Ascends are, IMO, definitely superior in a lot of ways. I found vocals, in particular to be clearer and better articulated on the Ascends. Moreover, the highs had a smoother character in my opinion, most likely from the silk dome tweeter in the Ascends, which I much prefer over the metal tweeter implementations that I have heard to date. The Energy's will trump the Ascends in the bass department, given the larger cabinet.
Given that, while your impressions of the C-3s were unfavorable I don't think that should preclude you from trying the Ascends, as the smaller bookshelf form factor and fabric dome tweeter implementation of the Ascends will probably (this is entirely conjecture on my part since I haven't heard ACIs) liken it more to the Emeralds than to the Energys. IMO, the Ascends are a superior speaker than the C-3s.
But to allay your own concerns, I would order the Emeralds and the Ascends, and compare them yourself to see which one you like better. While in this price range, out the shipping fee seems like a high price to pay, I think that knowing that you made the right choice and not worrying about, "what ifs..." is worth that price.
Side note: remember that you were listening to the Energys at Good Guys, which I have never seen setup a decent venue for auditioning so that is also something to consider about your impressions of the Energys.
As always, enjoy your auditioning!