Yes, I have done that EXACT 'upgrade', on my Syncro Westy. The height
increase was enough that yes, I can't park it in garages anymore, and
the speedometer now reads about 5% low (at an indicated speed of 65mph,
you're really travelling at around 68 mph.)

No real handling improvement per se (I was expecting one anyways). The
vehicle accelerates a trifle slower (still the stock WBX engine).

I really like the BFG A/T KO tires and have them on 2 of my Vanagons.
They are great in the snow.