Lifetime of extenders.. EX6200 replaced by EX7700

What experience do folks have with the lifetime of NetGear extenders?

My 6 year old EX6200 died slowly.. for a few months it would just degrade and/or lose the 2.4 ghz connection about once a day, and then a few days ago it died completely.. no connection strength leds and I couldn't connect through the lan ports.  No obvious cooling issues; it was in the open air in a reasonably cool room.  But I always wonder about electronics that run warm like extenders and routers.

On the upside, I felt the EX6200 gave me good enough service that I replaced it with an EX7700 and the installation experience with the NightHawk app was about the slickest thing I've ever seen in a home networking appliance.  The mesh performance is also very satisfactory.