Assuming he can get the video card support (I don't know what that is) it's fine in linux. No, I haven't come upon something as powerful as Premiere, but there are options. I use kino to edit my video, dvgrab to capture it, and mencoder to compress it. All these tools are either very well documented or straight forward in their use. There are also things like
http://www.mainconcept.com/de/mainactor.shtml
Which is supposedly an excellent commercial app. cinerella is claimed to be very high end and might challenge Premiere. FilmGimp is used to create some Hollywood movies recently, so one might think that to be a good piece of software as well.
So what's better? Well, depends on who you are asking, and what they do with their video. If this "guy" is having no problem in win, no crashes, and can process the video rather quickly, then I wouldn't bother changing. However, I personally took 6 hours off my editing time by switching to Linux to do it. To capture and compress my video (a 30 min clip) alone took me 8 hours in win. Now in linux it takes 35 minutes, 30 for the capture, 5 for compression. From there it's kino that takes me the longest time, and that's not kino's fault but my lack of editing skills
So, in the end, I guess I'd say have him give em both a try, see if he likes the tools available in linux, and if they make him any faster. At least then he can make an educated decision on which to use
Cool