I probably should know this but if you put an alt az mount on a permanent pier, do you still have to do an alignment for each observing session? I was reading a blub about a very expensive Planewave mount that was alt az and the advert said that it was the choice of many professional observatories. That had me confused, since it seemed like alignment would be a problem.
The other reason is that I was considering putting a scope in a location that I only could control remotely and I didn't think that an alt-az mount was an option. Please don't comment on the alt az vs. equatorial issue. That's a whole different issue.