Tony,

MY vote is for the "dashboard" style on top the cabin. If I could move my current instruments on my current boat, I would in a heartbeat! That way you don't have to take your eyes off the road. Also, if you pick instruments correctly, I doubt you will be punching buttons ever. At most you will want Boatspeed, Depth, and Wind (3 total). Granted, if you want to switch between apparent and true wind, you will be punching buttons, so just pick one and learn to love it!

just my opinion.
When I had my Ariel (#3), I mounted the depth on the aft face of the bridgedeck (in the cockpit well).
What a bad idea!
Whenever we were motoring out I liked to stand to get visibility, but then had to bend way over and stick my head down in the cockpit well to see if we were running aground (depth)! Poor ergonomics. The cabin-top dashboard (or even like the true-racers: on the mast) is the way to go!

-Keith