The two issues really are cost and do you fly much IFR.

An all electric panel is quite a bit more than a vacuum panel.
Also, it weighs more, two batteries, two alternators, more wire, etc.
If your autopilot works off of the Turn Coordinator rather than the HIS when
you loose the vacuum pump - o problem.  All in all both work just fine.
It's just money and weight.

PS This time around I spent the money and added the weight.

Joe