It's a big old mount - easily take a 12" OTA.

The problems are periodic error (you won't be able to take long exposure photos), alignment and portability. The mount is good enough but even at over $1000 you are not getting an observatory quality mount.

BTW - ever thought how high a newtonians focuser will be on a high German mount (when observing the zenith)? My guess is 10-11 foot, you'll need a stepladder.