It may be me, but "JFK" seems to my reading to be talking stove, not insert, at different points. The link "summit in action" looks like a stove to me.
I don't have a Quad 5100, but I have spent some effort researching its little brother, the 4100-I and the best I can determine the windows, front and side, remain clear within reason. A slow burning, smoldering fire will "smoke" any window, I believe.
As for how much heat any stove gives, I'd take the published test specs: efficiency numbers, BTU output, along with the how clean they are for comparison. I'd not take a comparison by a user, especially one who has settled on one. It is human nature to justify past decisions by defending them. That said, I don't know the published numbers for the PE Summit and Q5100, but they are easy to look up on the mfg web sites.