I would stop spending money on those speakers. I like Klipsch speakers and mods can help, but you'd be better off getting something in the Heritage line if you want to do mods.
The Crites tweeters are worthwhile if you're going to keep them. If you don't like the bass, get a subwoofer or two and high pass them. You can also try adding some weight (around 2 - 3 ounces) to the passive driver. I have not done that mod, but have read of it being done with Quartets and Fortes with good results.