I want to start off by saying since discovering AV123 around 3 years ago I've become a big fan of Danny's work. I've basically given up on most of the big league manufacturers. It's just so much more cost effective to DIY and I've learned so much about speaker designing since coming here.
I know Danny has his opinions regarding Sonicaps vs. other capacitors and I respect that. They really are great caps.
Still, I've been experimenting with Clarity Cap ESA series and found them to be very good as well. The main difference being a bit more warmth to the sound especially in the higher frequencies. They need some breaking in too as they can sound muffled and weird when you first install them.
Anyway, I had been using the ESA caps for my tube preamp and amps with good results and wanted to try them in a speaker crossover. The last pair of speakers I got that needed upgrading were my X-Omnis. Last weekend I finally got around to it and replaced the stock tweeter caps with ESA's.
I've got around 50 or so hours on them and they are sounding really good! In all of my other speakers I've got Sonicaps so I'm very familiar with their sound. Overall I find Sonicaps to be very close to neutral if a touch on the lean side. And in tweeter circuits they get even better when bypassed with Sonicap Platinums. I left the Sonicap Gen2 bypasses that came with the Omnis in place. I also replaced the stock resistors with Mills which also helped open up the top end.

The sound I'm now hearing from the Omnis is very similar to what they would sound like with Gen 1/Platinums installed. Still a touch warmer overall but with a very detailed and spacious soundstage. And once again I'm blown away by how good those Encore tweeters are when you have the right parts behind them.
The Clarity Cap ESA's are a bit more expensive but if you like a warmer flavor to your sound then they just might be the ticket for you.