I consider the Exage road crankset to be a slightly heavier 105 that's easier to polish because the OEM finish isn't real strong.

I have seen Exage road calipers from pretty basic single pivots, to basically unpolished 105's with the same QR.

I've only seen Exage 300 and 400 RD's on some Diamondbacks, and they aren't bad. Cleaned and lubed, they work fine.

The Exage SLR lever doesn't seem that different from a 105 lever, it's just a basic SLR lever.

I've only seen one Exage FD, a 300, and it was fine, as were the shifters.

I've rebuilt Exage hubs that came on a 3x7 RSX package, they were fine, and once rebuilt, work in an excellent manner. I still have one rear, and I'm holding it as a spare because it's a UG.

That is 100% of what I know on the matter.