YUMMY!!! I ate smallmouth for the first time this year, changed my life! I was one of the guys thet would have busted your balls for keeping a few, now I am all for releasing a few to the grease! 
Besides, as mentioned, they typically take over a body of water by outfeeding everything else! Lake Goodwin is starting to tip that way, fewer and fewer largemouth! Everytime I go there now I keep a limit of smallies if I do well.
Nice work! 
They don't typically take over a body of water. Any fish can take over a body of water, but the right factors have to be in place. There are a lot of bodies of water where SM should be harvested, same as bullheads, carp, pike, lake trout, walleye, rainbows, pike minnow.....
If it's legal by all means go for it. I'm almost 100% catch and release on bass, especially females, but I'm not going to jump down your throat. And they do eat pretty well, we keep smallies from the river every year for a fish fry.