For years I've been using a Delta single bag DC. I've been watching out for a a little bigger system for a while now, but everything I've been seeing is just too big for my space. With the single bag I can fill it in twenty minutes running the planer, and changing bags is kind of like changing tires...I don't care for it (even though it only takes a few minutes). I'm looking for a larger two bag DC with a 5hp motor and the ability to hook to multiple machines at once.
I do use a quiet shop vac hooked to my miter saw with a vacuum switch that turns the vac on and off each time the saw runs. It works great for that. A shop vac on a larger machine not so much. Grizzly makes several smaller dust collectors that you can buy new for under $300. All of them would be far better than a shop vac, and might be a good option for you if you're unhappy with the shop vac set up..