Hi Chris,
Thanks for a very useful reply.
The polar aligning tube has worried me. I've seen suggestions that a polar scope upgrade may be in the planning (but when?)
I've looked at the forums you suggest and have come to the conclusion that I would probably have to buy a new tablet.
I do want to do some photography but my opportunities are limited, I have to travel to find an observing site. So set up time and ease of transport are important to me.
This is what drew me to this mount. However, I am also concerned about it's payload capacity, recently seen it quoted as 5kg. (although most list it as 6.8kg for photography)
I have finally decided to spend somewhat more money and go for a Skywatcher EQM-35 pro. (higher payload, polarscope, synscan controller, sturdier tripod)