The relaxed seat tube angle is to keep the ratio between seat height and effective top tube length better over a larger range of seat height. This should allow a better fit for more people with a fewer number of frame sizes. Aegis was one of the first carbon builders, small company in Maine. The cost of a frame mold is very high, so they tried this. Now it's just an orphan, the company is gone. There are a lot of other things I like about the frame, so I can overlook the "meh" aesthetics of the seat tube curve.

The wheelbase is similar to other high performance road bikes (that you might ride all day long), comfortable and responsive. I have a later year geared version of the same frame, like it a lot that way too.

Coincidence, the Allsop company is gone too, so we have two orphans here.