Scale doesn't matter to everyone in the same way. Although from a toy play perspective, I must admit that it is nicer to have a Megatron that's the same size as Optimus so they can go toe to toe with each other better. Having said that, Deluxe Megatron is packaged in a VS. set with Deluxe Optimus Prime -- so in buying DLX Megatron you're gonna end up with a same sized Optimus Prime anyway. Unless you just want a Megatron that stands taller than most other Decepticons.

I have both Deluxe and Voyager Megatron... they're both pretty terrible toys, but the Voyager is substantially worse (at nearly triple the price). But Voyager Megatron is a lot easier to find... and you might be able to find him on sale. I saw some Voyager TFPRiD leaders at Target just a few days ago... I scanned one of the Deluxes and it had been reduced, so I suspect that the Voyagers might be too. I paid full price for my TFPRiD Voyager Megatron, and to this day I still facepalm myself for it. Guh.