We have been using snap-shot for several years. It reduces landscape maintenance hours dramatically, and keeps the beds looking the same as if dozens of manhours were invested. We apply early, before mulching in March, and reapply in early May. We have had some success with nut sedge using double the stregnth of roundup in a stick sponge applicator.
Ordered snapshot last year and applied to some flower beds but not all. Where it was applied very little weeds to pull in the spring. Where I did not use it the weeds were a nightmare. I wish there was something I could use for nut sedge control that would not harm daylilies.