I Currently have Jm lab Micro Utopia. I'm driving them with a Cary sli80 integrated tube amp. I love the JM Lab sound, but I've only compared it to the B&W, and Revel products. I much prefer the JM Labs. I'd like to stay with tubes over the long haul. I'm considering the mezzos used. What other options should I listen to?
Legacy Focus 20/20. You may be surprised how these compare with the Mezzos and for less money.
I've heard the Mezzo's many times and come away loving them more and more everytime I hear them. You can't go wrong with JMlab. I don't know how much you are looking to spend but with JMlab replacing their entire Utopia line you can get a really good price on a brand new pair of Mezzo's. They dropped the retail to $9995 till they are all gone and you may be able to get a dealer to come down a little bit off of that as well. Just depends on what kind of relationship you've got with him I guess.

Good Luck,
I've lived with my Mini-Utopia for the last two years and loved them every minute for the last 1 1/2 years (break-in period is 6 months). I drive them with VAC Rennaissance 30-30 and Airtight preamp. I don't know about the micro but the mini has glorious lively high and tight bass (not deep though). May be the Mezzo would help you.