Ardene have comprehensive facilities and loads of space both outside and in the examination area. I have never used Kessock so can't comment on them. I suspect the journey would be easier to Ardene with the new bypass.
I can't comment on Kessock as never used them, but am pleased with Ardene. Super quick to get there from the Bypass. As far as possible, you always get the same vet for your horses, so they get to know them. The vet I get is down to earth, knowledgeable, and doesn't try to sell me silly things, while making sure I know all the available options. Had to take pony in for leg scans etc., and found the facilities easy to access, the prices fair, and the service good.
Kessock vetted my horse and I was pleased with them for that. But can't comment otherwise. People round here use them for anything that isn't routine or emergency (which are covered adequately by the local vets) and on the whole I have heard good things.
D1 has used Ardene. She was happy with them - they listened to her and found something to help Grey Mare (she can't have Bute or Danilon). The prices weren't too bad either.