If you mean dates published on GSO website they are just different for each aperture. According to their website 8" should be available in April, 6" in May and 10" in June.
Wish GSO/Skywatcher/Synta would upgrade their mounts to be worth putting a RC imaging scope on!
EQ5 - 32 tooth gear, HEQ5/EQ6 - 64 tooth gear.
Losmandy GM8 - 180 tooth gear!!!!!!!!
Now that would be nice!
Agreed doug, the problem is, more teeth = smaller sized teeth = stronger material and better QA required... All that boils down to is increased cost. Hence you can buy 2 HEQ5's for the price of one GM8.