My experience w/ MSMA
I've got bermudagrass and always used MSMA to kill crabgrass and grassy weeds after my crabgrass preventer tuckered out in the summer. For broadleaf weeds I always used Weed Out from the co-op, or even just any weed killer from Lowes that said it killed broadleaf stuff and was ok to use on bermudagrass. For crabgrass and grassy weeds, MSMA was the bomb - it'd kill it w/ one application and wouldn't slow down my bermudagrass at all.
When MSMA went away, I called a landscaping buddy of mine. He recommended something called Weed Out With Q (the "Q" stands for some long chemical word). He warned me that it wasn't going to be nearly as good as MSMA was, and he was right. When you spray the first time, it'll knock crabgrass down and yellow it up - along w/ the bermudagrass around it - but won't kill it. Usu have to do a second application a week or two later. Basically, for about 3 weeks your bermudagrass will brown/yellow up some, then eventually turn green again and the crabgrass will be dead.
If all you're trying to kill is broadleaf stuff, either get some Weed Out from the co-op or anything from Lowes that says it kills broadleaf weeds and is safe on bermudagrass. Most of that stuff is pretty foolproof and and won't impact your grass at all.