I don't do a lot of this, but when I do I just use a cordless circular saw and set the cutting depth so it's about 1/16 - 1/8 deeper than the thickness of the drywall.

Use a long level or straightedge to mark some lines and then make the cuts.  I don't have dust extraction attachment on my saw so it makes a big mess, but like NNF it's usually during a remodel so that doesn't matter.

You will hit some nails/screws but not usually a bid deal...

Setting up a track saw seems cumbersome and overkill for this type of work.