I was getting 3+ flats a month due to goats heads and glass. I was running ultralight butyl tubes with non-puncture protected Compass tires. I loved the performance and ride quality, but the flats were a real drag.
I added SlimePro (which is a latex base product, not the crappy green stuff) and got no more flats. A side benefit is that the tires hardly ever needed air. When I finally replaced the tires, I found the tube peppered with holes. It was a bit messy, but to have performance and be flat free, not a big deal.
With most latex based sealants, you have to add more every 3 months or so because it dries out. I want to try CafeLatex which is a synthetic latex base, which should not dry out so fast.