As far as cutting track to custom lengths, using a dremel and cut-off wheel can be tedious if you have a lot to do.
In addition, I'm not sure they make a cut-off wheel with a large enough diameter to cut across all 3 rails at once (someone can chime in if they know). That's important because trying to line up two or three separate cuts can result in an uneven overall cut.
You might want to check out the drillmaster line of small cut-off saws at Harbor Freight - one with a 2" wheel and one with a 6" wheel. They both have clamps to hold the track in place and an angle guide to make angled cuts. A little pricey, but quick and accurate.
