Sanders magtech or odyssey kismet

I am looking for a "last amp purchase" one I can keep for 20+ years and pass down to my son someday.
This probably won't happen, but it is a very good possibility.

I have gone through numerous over the years, with fairly bad luck with them, UNRELIABILITY!

I have narrowed it to these two amps. I know they are both very good.

I would like thoughts on them from other audio people as yourselves.
Before you say these speakers suck, I wanted to say I auditioned A LOT of different ones before settling on these. I use energy rc-70's, only about 45-50 hours on them, nowhere near broken in yet. I LOVE their sound, period.

People say these amps are too good for the speaks, I think not.
Maybe sanders preamp.

I have heard magtech sounds thin, and others say it's amazing.

Anyway, what's your thoughts on odyssey kismet monos or sanders magtech. Thanks
Satie IS an audiophile (purist analog lover, with a tube amp on the M/T panels of his Tympani’s), and the Crown he has on his T-IV bass panels is the discontinued Macrotech 5002VZ.
ok. what did he do about the mismatched input sensitivity of the tube amp vs. the Crown? Or, are the input send of both amps the same or very similar so that they both output max power at about the same input voltage level? 
My understanding is that if the inp sensitivity of both amps is different you could end up with too little bass or too much bass....

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Can’t speak for everyone that actively bi-amps, but- I’ve always used a crossover that enables me to adjust for disparities between amps. My first was one I built using DeCoursey boards(1980), for my home system. I ended up selling that whole system to one of my regular shoppe customers. Used a Dahlquist DQ-LP1(modded), for the next 25 years. I’ve had my TacT RCS 2.2Xaaa(modded) ever since.  I loved the Dahlquist, but- the acoustic nightmare in which I'm now forced to listen REALLY requires me to use room correction.
Bombay, Satie uses resistors to correct for power amp voltage gain differences. I still have my Dahlquist DQ-LP1, which I use for the bass leg only. Brooks Berdan tried to get me to sell it to him for the longest time, but I knew I'd need it eventually.