MissGXP, "filler" is in the glaze product. Think of it as a special kind of wax. There's no danger at all whatsoever (which is why I recommended it to you).
Edit: Like a wax, however, the glaze will eventually wash away and will need reapplied.
Daniel,
I have the Makita 9227 and I love it. It's light and has a curved handle that rolls over the top of the polisher, which I find allows me to polish on odd and vertical surfaces much easier and with more accuracy than with side handles.
For quite awhile I used a DeWalt polisher but it weighs something like 10 pounds. Ten pounds doesn't sound like much...until you're trying to hold it up on a vertical panel while it spins a head at 5,000 RPM across a 6-hour exterior detail on an SUV.
The most important aspect is quality. Buy a known brand after researching the options on each one (DeWalt, Makita, Hitachi, Porter Cable, and a few other misc. brands). You'll need a kit for it with backing plate and pads. I LOVE Lake Country pads...they truly are the best I've ever used. Also, nowadays they've perfected wool pads to the point that you can actually finish with wool without fear of holograms/haze. The benefit is that it is pretty much impossible to burn through a panel with a wool pad.
Anyway...I'm getting off-track. Here are some links to get you started:
http://www.coastaltool.com/a/makita/9227c.html?id=RT54avj7
http://www.coastaltool.com/a/lakecountry/buffing_pads_8.html?id=RT54avj7
http://www.autogeek.net/lake-country-ccs-pack2.html