I see you've already made your decision to buy the Makita, great choice! You really can't go wrong with ANY of these machinces.
But, for anyone else that is wieghing this same decision, I'll give my input. This comes from a full time detailer that uses a rotary practically everyday. I own the Dewalt, 3 Makita's and the lightwieght Flex rotary.
Initally I bought the Makita because thats what everyone else was using. Works great, lightwieght, soft start, easy to use.
Next I bought the Dewalt just to give it a shot since thats what a lot of others were using. First impressions.....HEAVY! Aggressive! Great machine, but way to much for me. I used it for a while, then the speed dial broke, so I tucked it away a couple of years ago and haven't touched it since. went back to the Makita, and actually bought a couple more over the years.
Flex lightwieght rotary, what can I say, lightwieght(just as the name says), about a pound lighter than the Makita. That really helps when you're doing vertical panels! Small design, I have medium size hands, so this is another plus for me. Very efficient machine!
All in all, the Flex lightwieght machine is my favorite. I use it 99% of the time. The down side to this machine, as Todd pointed out, is it does tend to get warm. This really doesn't bother me as I wear gloves when buffing(Mechanics Vert gloves, thin and comfortable). For this reason, I use my Makita when I have any heavy correction work to do. Basically, anytime I need to break out a wool pad, the Makita comes out of the bag. But beyond that, the LW Flex does ALL of my buffing, ploshing etc... It's a GREAT machine!
Nick