I installed my Koni's this weekend. These things are awesome! My wife has already autocrossed on them today, and she liked them a lot. I can't wait until I get a chance to abuse them a little.
I haven't seen this before, so here is a write-up on how to do the Koni insert installation into the OEM strut housings. It's not difficult, just takes a little time and patience.
http://www.4g61t.com/jason/articles.php?pg=3