Polyshades is CRAP! I've used it for a few projects (I didn't know better) and got some good and some horrible results. The problem with that stuff is that it's not a stain as much as a tinting agent. You are basically painting on a thin layer of semi-transparent film. If you try to sand it, the stuff peels off and makes a horrible mess. It's hard to get an even coat and tends to bead up creating dark spots/streaks.
I've found that it's better to use a real stain! Oh, and don't skip the conditioner! Without that step, you WILL get uneven splotches all over the place. Take the extra time and do it right.
Sand, Condition, sand, stain, sand, seal...BEAUTIFUL!
And tack cloth is very useful too!