It worked flawlessly for me. I just plugged it in and fired up Garage Band, and I was off. There's a tiny bit of lag if you do it that way -- they provide special "low latency" drivers, but my keyboard and mixing skills aren't good enough to warrant the extra hassle. Professional musicians might feel differently.
Re: the DVD burner. You're going to have to get a copy of Toast, and even then, you won't get full use out of the burner. Apple intentionally crippled iDVD so that it only works with their own (internal-only) burners.
Good article overall, but it's not fair to blame the Mac just because you wanted to buy a bunch of new toys (like the LCD). ;-)