Pro's: flawless treble
cons: cost me $400 aust each!
I have listened to the:
- revelators by scan speak.
- seas exell tweeter
- top end vifa tweeters
- even the r3's by raven
- also the newer tweeters by the guy who designed the ravens
and i would still say the r1's sound best in my ears.
I dont really know why they are so good but there is basically nothing wrong that you can pick with them -
they display the sounds so well separated its not funny...
Play so high and so clearly and so loudly it makes me want to cry

go listen to a pair some time!