Yeah, the lack of harness slots is a slight concern for me, but I think I'm going to try the Elise seat thing for a while and on a few track days to see if I could live with that (aim with mine is probably 80/20 street/track). If it doesn't, I've had my eye on Corbeau's Elise replacement seats for a while, and several of those do come with harness slots.
Not surprised you had to hammer the tunnel either. Led to believe the stock seats are actually offset on the bottoms to account for that, and since regular aftermarket seats tend to be symmetrical it takes a bit of coercion to get them to fit. The other reason I like the idea of Elise seats is that they're tiny so seem to fit without any modification...