Not to dampen the discussion really, but this issue has been debated, talked about, discussed, speculated upon, every which way possible. Only Festool really knows and they aren't talking about it (which in and of itself has been discussed many times).
I suggest that in order to help the OP as much as possible that this topic is kept hard on track with reports from hobbyist users Kapex longevity or Kapex problems.
Otherwise it will become another Kapex general discussion topic that will not benefit the OP anymore than all the other similar topics. Which I gather he has already read.
Thanks,
Seth