Hales tweeter?

So I'm being told by just about everyone that the Seas Millenium would not be a good drop in tweeter for the Hales tweeter. Can anyone reccommend a good tweeter that can be an upgrade to what's in the Hales T5's and 8's. Apparently the Hales tweeters are pretty good but I was wondering if anyone had advice on how to upgrade this tweeter. What would be an easy tweeter to just drop in, no crossover reworking, just replacing tweeters for tweeters. There are tons of tweeters out there but the Hales has an outer diameter accross of 110.4 mm so alot of the Vifa's wouldn't fit without cabinet work. Does anyone have ideas?
Leave it alone unless your prepared and capable of reworking the crossover to match the tweeter. Swapping drivers and making them blend as one is not just a simple level match. You could be real lucky though. Tom
I got lucky with the crossovers. I think I'll not push my luck. Anyhow I'm learning that the Hales tweeters are pretty good. Not just because I think they sound good but others claim the tweeters to be very good.
I decided to push my luck and install the Millenium. So far so good after 6 hours.They are smoother yet still very detailed. It is like I am listening to a more sophisticated sound. It's hard to explain it and I don't know if it would look any good from tests and on paper but it does sound quite nice. I don't find the tweeter soft volume wise as it seems to have sufficient output and satisfiying sound. Some said the sound might be "dark" or lack some some high end detail but so far I do not find this to be the case. I do realise that the tweeters will change over the next week or two and there is the possibility I won't like what I'm hearing but that is just one of those audio gambles I decided to take.I found the origional Hales tweeter had a little too much high end frequency almost being harsh which is why I went through the excercise of changing the tweeter.I do seem to find that the tweeters crossover lower but they still sound good. The speaker sounds like a unit as opposed to three drivers out of wack. I'm happy so far.
Thanks for everones help.
300 hours play and my speakers arte singing. I really enjoy this new sound. It's an improvement top to bottom. The speaker has a whole new characteristic sound which I am enjoying.I am enlightened on just how much a tweeter can change the sound of a speaker one way or another.