Martin Logan reQuests vs newer Martin Logan offerings

I owned ML's for almost 15 years. The stator panel definitely has a shelf life. I'd communicate with ML about the Requests. If the panels need changing out, that's not a inconsiderable cost.

Ouch yeah good point.  Any idea how much that would run?

Call them and ask!

I started out with ML Preface (non-electrostatic) for my fronts years ago. I quickly moved to a pair of used ReQuests which sounded great passively bi-amped. Currently I have the Summit Xs with their integrated pair of powered 10" woofers. The ReQuests are now my surround speakers. 
The ReQuests displayed a wider soundstage in my room. The Summit Xs are a bit brighter and more detailed. Their main difference is the bass is so much more natural and integrated. I have the Summits powered with a 100 WPC Rogue Atlas Magnum II tube amp. It sounds better than any SS amp I've used.
I am still enjoying the ReQuests with their original panels, but have a spare pair of lightly used panels for backup if needed. If you keep the panels vacuumed, they should last for years. As a last resort, you can pull the panels and wash them. (See Martin Logan's Owner Site).

If you keep the panels vacuumed, they should last for years. As a last resort, you can pull the panels and wash them. (See Martin Logan's Owner Site).

So their limited lifespan is mainly related to dust accumulation? Or is it something related to repeated micro - arching (due to dust particles) identifiable by the typical low level buzz noises sometimes heard when putting your ear next to the charged panel when no music is playing?  How often is it OK to vacuum them? (I\m doing it every 2 months or so; I wouldn't mind doing more often if this would prolong their life)