I've used the Makita BO6040 a few times before it was permanently borrowed....
At the time I didn't much care for either mode. I first tested it out while buffing out this truck,
Custom Classic Trucks Magazine: 1956 Ford F-100 America's Most Beautiful F-100
http://image.customclassictrucks.com...mage_large.jpg
Because it was the first time I had used the BO6040, and it didn't feel comfortable in either mode, and because the truck was
important I put the tool down and used a rotary buffer to knock out all the heavy swirls and then finished out with a DA Polisher.
It's not generally a good idea, nor my practice to learn how to use a
new-to-me tool on something that's important like a black show truck. I always say,
"Don't learn to use a rotary buffer on a black Viper"
Not that a person can't learn to use a rotary buffer on a black Viper but it's a better idea to learn how to use a rotary buffer, or any type of tool on something that's not important to you, like a beater, a panel off a car or even a daily driver grocery getter type vehicle. Then once you get comfortable with the tool then go for the black Viper or fill-in-the-blank.
I drove from Apple Valley, California to Escondido, California, (approximately 130 miles one way), which was where the car was located and only took the tool along to test it out. After buffing half the hood and getting a feel for the tool I chose to stop using it and switch to tools I was comfortable and already proficient with.
Shortly after that detail project the tool was stolen and never replaced so I would want more time behind it before forming an opinion.
The Flex 3401 is specifically built for paint polishing, it's not a multi-purpose tool like a DA Polisher or a Rotary Buffer and it has a strong loyal following and a time-proven quality and performance history.
:)