I'm looking for a decent alt/az mount to put the ED80 on and the first one that came to mind was the vixen porta mount but after reading a few reviews there are 2 main things that put me off.
1) you need to use an allen key to adjust the tension on both axis
2) the slow motion controls look a little short?
the Skywatcher AZ3 looks a bit more user friendly but also looks pretty flimsy in comparison with the porta mount which can apparently hold a 6" newt
Vixen porta is great with the ED80, the short knobs can be replaced with the flexible ones if you wish, I have both but after initially using the flexible ones I have reverted back to the shorter stock items.
The GS clone mount looks similar and although the legs are more sturdy, overall I believe it isn't quite as rigid due to the length of the mounting arm.
The friction isn't an issue, I've never had to adjust mine and provided your OTA is balanced correctly friction isn't used to hold position (the ALT axis is perfectly balanced, unlike the AZ3 which has the OTA positioned above the ALT axis and tends to overbalance.
Because of it's design the Az3 relies on friction to hold the OTA in position. I bought an AZ3 before the Porta's became available, I found it unusable with the ED80 due to balance issues caused by the poor ALT axis positioning.
I have the Bintel Skyview Alt/Az Porta-mount clone...I use it with my ED80 and binoviewers.
I have the flexible knobs on it.
While I am not an expert refracter person, I have not had any problems with this mount. It is sturdy and well made and seems to work well with the scope. I use it primarily on the moon to good effect.
