Mandrake,
I have both kits as well so hopefully I have an educated response for you. The DAS pads are made from a softer foam than the SFX pads. I guess you could say that the DAS are like the baby step/learning pads. Not that a PC generates much heat, but, the DAS pads disperse the heat better than then SFX thereby insuring that you won't harm the paint at all. The SFX pads, being a bit stiffer, will generate a bit more heat but not so much that I would worry about it.
The SFX pads are also uniquely matched to the SFX series of polishes. Not that you can't use the
Sonus polishes with the DAS pads, I just feel that you get better results with the SFX pads.
Personally, I like the SFX pads a bit better since they seem to work on defects a tad bit quicker, but, either one you choose should serve your purpose well.
Feel free to hit me up with a PM if ya have other questions.