The replacement part came in for the McIntosh XR-14's! So of course it's in and I took them for a spin.
I compared them to the XR-16's and my Sansui SP5500x speakers, AKA my "keeper" system. The Sansui's are a lot more efficient, but have a distinct, slightly warm-ish signature. They're clear with good full range resolution, but they aren't as transparent as the Mc's. They're definitely not quite in the same league as the Mc's, but they're still very good (and good value too!) and deserving of a spot in my keeper system.
The XR-14's have the typical (for the brand) low near-zero distortion that I was hoping for. Very flat response down to about 100hz, with sweet (but even and balanced) highs and mids. They sound similar to the XR-16's except for low and very low bass response. Long story short, they are kinda thin in the deep bass department. They really do need the MQ102 equalizer that was designed for them, but in a pinch, adding 6-10db of very deep bass and 3db around 100 hz will do most of it (or just using the loudness button the the 1980 - that was pure magic). On an aside, when I had them apart, I looked at the crossovers. Those things are incredibly complex. Looked like over a dozen discrete components. Very beefy too.