I've been using Taco zone valves here for years on a single circulator with minimal problems. The newer style motor heads are a lot more reliable than the older ones were, I think someone else stated that too.
I like the zone valves as opposed to individual circulators because if one of the valves fails, you just pop the old motor off and snap the new one on, the valve stays permanent. No tools required, takes longer to put on your socks, and no mess whatsoever.
Again though, to each their own.