Electrostat - M-L; Quad or Soundlab - reliable

For most users, Quad panels last 15-20 years before requiring refurbishing. I do not consider that to be unreliable.

According to Roger Sander's the Innersound panels have never failed.

I am a soundlab m2 owner and have not had any reliability issues at all; my bias adjustment is checked on a regular basis and unplugged when not in use.

I have two sources of information re: Soundlab reliability.
1. Two of my friends have Soudlabs - M1 and M2. One had to ship his back for repair( the M1). They are now for sale.
2. Check the ads on Audiogon. A high proportion say; For sale, just back from the factory with .......
I strongly suspect that few pay to have their heavy expensive Soundlabs shipped back and THEN sell them, unless there was a problem. On the other hand, I have become a suspicious person (by starting out as a trusting one) .

I can attest to the reliability of the Innersounds. The stats are practically bulletproof. No arcing, no issues with dust or humidity. Yes, Innersound has closed it's doors, but Roger Sanders is in Colorado, and very willing to help you out, if a problem arises. The Innersound Kaya's have dynamics that will completely blow away any of the other speakers that you are considering.
There is a pair currently for sale on Audiogon, that is a steal.
If electrostats are what you are looking for, I highly recommend considering these. I have had mine for about six months, and for the first time in my audiophile career, I can say that I am done. There, I said it.