McIntosh MX 119 Preamplifier vs Adcom GFP 750

The 750 is quite old now, devices eventually drift out of spec.  I would avoid that.

If you're looking to spend 800-900, there should be some pretty good options.  I'd suggest a brand new option.  If you know anything about crosstalk, SNR and other specs, the Freya + by Schiit Audio has stellar performance.  

It's also a tube preamp, but it has two other modes of operation in which the tubes are not engaged.  The sound is so transparent its jaw dropping at times.  I've got it with a solid state amp and the combo is end game.  

How long do the tubes themselves generally last ?
Do they all degrade at the same rate and just replace all of them when its time.
The other solid state I'm considering is the McIntsosh C47.
thx 
for info

It doesn't have any tubes, so they should last forever.