Upgrading my tweeters and need some opinions......

Absolutely great tweeters on the cheap (all are very solid recommendations IMHO):

The ring radiator is one of the easiest to integrate into quite a few different crossover configurations (ever wonder how Polk managed to make it work so easily?). It is also cheap for its performance and cost perspective.

My favorite inexpensive dome (that's under $40!) is a custom pure silk dome made for GR Research. It embarasses many $150+ silk domes from companies like Vifa and Scan Speak. Truly high end sound for damn near nothing.

The Cantum Ribbons are starting to gain quite a bit of ground as of late and probably beat anything else that's a true ribbon from a cost perspective. (Those damn Chinese are just making everything high end afordabale nowadays).

Another up and comer is the new Neo flat driver from BG just one a comparison shootout of tweeters under $100 in terms of distortion, overshoot and impulse measurement(around $45 I think).

As for the hypholutant drivers such as the Dynaudio Esotar or the the $3,000 diamond tweeters...well, I'm sure that some others can chime in here ;-)

I'm using a pair of LPG 26t titanium domes in speakers
that I built. I think they're great.

I think you should direct your question to the experts at the www.Madisound.com forum. Most likely they will tell you that you should hear examples of all of those options, and then form your own opinion about the +'s and -'s of each type.

Then you will certainly need to share your crossover, other srivers and box dimentions with one of these experts and have them make a first attempt at updating your crossover to go with the new tweeter. Then you may need woodworking to make it fit correctly.

All in all, I wouldn't try this unless you are prepared to experiment and possibly wind up with worse sound than you have today. I think its time to look for brand new speakers.

Good luck,
Bob