PIONEER RECEIVERS: Which One Do I Keep?

For a few months now, I have been using a vintage Pioneer SX-780
receiver in pristine condition.  I have really enjoyed using this
receiver and really like its excellent, warm sound for both analog and
digital sources.

But now fate has smiled upon me and I have just discovered a vintage
Pioneer SX-750, also in pristine condition.

I will keep one of these receivers and sell the other one.

But my question is: Which one should I keep?

I thought I would ask some of you kind people, since it is very
possible that you know some details about these receivers, technical
or otherwise, that I might not know.

I understand that the power amplifier section is slightly different
between the two models.  What is the difference?  Does the difference
matter, either in sound quality or longevity?

I must admit that I haven't listened extensively to either one of
these receivers, and I certainly haven't made a "head-to-head"
comparison, but I will say that they both look and sound fantastic.

Which one would you keep and why?

Many thanks in advance......................