Magic returns in seldom used bookshelves?

I’ve had the Sierra2’s and very much enjoyed them. Heard nothing but accolades for the ex upgrade.
Since you like the Sierra sound, have you considered the towers with their superior RAAL tweeter?

This stuff happens more often than you’d think. I could share an anecdote on some Vandy 2Ce Sig IIs that would make your experience seem rather vapid but some here would get bent out of shape. 

Trust your ears.

Keep swapping them, without regard to "break in", and learn. 

Erik,
Genuine words of wisdom. That approach and philosophy could alleviate so much angst and regret/anxiety. Maybe too simple for some to adhere to.
Charles

I've always been curious about the Sierra's -- right up to the point of buying them. I bought Salk SS6m's. I love them.

One consideration might be the speaker-room synergy or lack thereof. One speaker is a tower and the other is stand mount, no? Perhaps there's something nimble and direct about the Ascend which the Salks, in your space don't have? My Salks are standmounts, and they beat out a variety of towers. 

If I were you, I'd be very sure the Salks were no longer your cup of tea. I think Jim makes heirloom, high quality stuff and I'd expect it would take a long time to tire of them. Still, never know. Sometimes a divorce is just what the doctor (or lawyer) ordered.