Go with a mid-cost type microfilter. I've got an MSR SweetWater. The tablets will kill everything (if you wait long enough), but the microfilter helps get rid of the floaties, sinkers, general other crud, makes the water taste a little better, and helps make the purification go faster.

Its never a bad idea to wait the full 4 hours, but if you're in a fairly remote area in most places in the U.S., you can probably get away with waiting for the minimum amount of time to pass. The 4 hours is for some of the harder to kill, yet more exotic (less common) critters.

Also, make sure to let a little of the chemical water seep through your water bottle cap a few minutes after the tablet has dissolved. If you purify the water in the bottle, but have some of the contaminated stuff in your cap thread...