Anybody have opinions on supertweeters?????

After the recent article in Stereophile, I'm considering giving a pair of supertweeters a try with my Martin-Logan CLSIIz's. The options are:

1. MuRata
2. Townshend (ear-usa)
3. Tannoy

Does anybody have experience with using any of these with electrostats? Where are they best placed? Do they create any phase or timing issues??

Thanks,
Harry