The mount is unique in that you can actually aim the second, top mounted scope independently in altitude and azimuth. You do need a counterweight for the scope on top or it throws the whole thing off balance which is why i wouldn't go over a 15 lbs. or so payload on that side.
With a C-6 on the fixed end and an Orion 120ED on the adjustable side (and 10 lb. counterweight) it balances out nicely. The slow motion controls are smooth, although i did make a slight modification to the altitude slo-mo control as there was too much play in the worm gear when i received it.
Quite stable with the pictured load, it's rated for 15 Kilos per side but that seems overly optimistic - i wouldn't go over 20 lbs. per side, especially with this tripod.
Overall, i am impressed thus far. It's a great mount to do comparison testing between different telescopes.