First, my 2007 MacBook Pro natively displays 1920x1200 resolution, which is slightly higher than 1080p, at a 16:10 aspect ratio instead of 16:9 (slightly taller, hence the extra 120 lines of resolution). So that's not true.

The software he uses (Vegas) does not, in fact, run on a Mac. However, Avid (Windows/Mac) and Final Cut Pro (Mac only) are substantially more powerful than Vegas (though Vegas is still very good).

I believe he's referring to iMacs and Mac laptops when he says "you are stuck with the very small amount of available components." This is simply not true with the Mac Pro desktops, which is what the majority of professional film editors/CG artists work on.

I don't know why he thinks Macs aren't as fast as PC's. Possibly he's saying you can get a faster PC for cheaper than a slower Mac, which is true. But you can get very fast Macs - my laptop has a dual-core 2.6 GHz processor, 4GB of RAM, and a 256MB video card (admittedly, the video card is quite outdated now). You can get even better specs with a current-gen Mac.

I've only ever run into trouble with video work on my laptop when I'm working with too many layers of 1080p video. Straight editing, color correction, audio design/mixing, and effects work pose no problem.