Stiffer? Yes. Better? Not necessarily. Teg coilovers tend to be sprung about 100lbs stiffer in the front (great if you've sapped a B18 or summat) and 50lbs stiffer in the rear (great no matter what) compared to Civic sets, and the struts will be valved accordingly. The only caveat is the stiff gear up front, which really isn't called for. Tegs need it to accomodate a B18 and a ~3000lb curb weight, and Sols just don't.

You'll definately give up a fair share of compliance for an almost painful loss of bodyroll (many road irregulariites will now be felt in your teeth), and the Sols tendency to understeer will be somewhat worsened, at least until the swaybars can be adjusted or changed to compensate-- and even so, you'll not get anywhere near neutral handling. She'll always be nose heavy with 450-500lb springs up front.

Of course, you could just throw Civic springs on the Teg struts for some interesting effects... the over-damping would be a gold key entrance to Scrape Town, though.