The best center channel speakers I’ve heard have had a dedicated midrange driver located below the tweeter. You’ll notice the Aperion is configured this way, and I’ve also heard it in a system I’m familiar with. It’s one of the few center speakers I’ve heard (especially at this price level) that sounds completely full and natural, and there was nothing that immediately jumped out at me as a notable coloration or limitation. That’s why I feel very comfortable recommending it, and I haven’t heard any of the others you mentioned. But just taking a quick look at those similarly-priced models, I have some thoughts FWIW.
I’m sure the similarly-priced Ascend is a nice speaker, but it doesn’t have a dedicated midrange driver so for that reason I prefer the Aperion. Also, note that their more expensive (and much larger) center speaker does have a dedicated midrange driver. I think that says something. I’d rule out the Chane for the same reason.
The Emotiva looks interesting, but all else being equal (which it’s not) I’d choose the Aperion’s silk dome over this speaker’s ribbon tweeter because at least it’s more similar in design to your speakers. Then there’s the 3" midrange driver used in the Emotiva, which I’d be concerned doesn’t have the range to believably portray lower mids and dynamics. I’d prefer the 4" mid driver in the Aperion for those reasons and because I know from experience it delivers in this critical area. Last, the Emotiva is about 8.5" tall, which I’d think may be an issue given your stated space requirements.
Hope this helps at least somewhat, and again best of luck in whatever you decide.