Just tried 6.5" pads with the Griot's Garage DA...

[embolism]

That's a great question, maybe one of our forum members with expertise in watts, amps, volts, etc. might have some insight?

Besides the electrical power variables, there's also the design of the Free Floating Spindle Bearing Assembly, plus the design and even size of any other moving parts that contribute to the drive action of these types of tools.

One thing for sure, companies pay attention to trends and popular topics on discussion forums, so one question I've asked previously I'll ask again...

Will Porter Cable or Meguiar's make any changes to their tools moving into the future?

Just looked it up on how stuff works:

http://science.howstuffworks.com/environmental/energy/question501.htm

so in a nutshell, for a given voltage, the GG6's higher amps will produce more power than a machine with lower amps. From the examples given in the link above, the same watts or power can be achieved by a motor with lower amps, but it requires a higher voltage (water pressure).

Mike, you were also correct in that the parts, especially the wires used for construction, all contribute to resistance and the overall electrical efficiency of the tool itself, again for a given voltage and motor amperage

Pretty interesting near the end when the article talks about how the auto industry is moving towards a higher voltage standard in order to power all the electronics in today's cars...

[Jethro]

My first buffer was the Megs G110v2, and it did fine with 6.5 inch pads. After a few months, my power cord messed up, which I feel was caused by its being crimped constantly by storage in the too- short bag it came with. During a sale, I then bought a PC with the heavy-duty cord. This one seems to work better with 5.5 inch pads. During the Memorial Day sale I bought the Flex 3401 and Holy Smokes! I'm using 6.5 inch pads with it and its power really speeds up the correction time. This tool is a pleasure to work with and is the one I should have purchased to start with!