I have both and not an issue for me unless over feeding. Also with lower pH and lower GH/KH, I think they may not be as big of issue, as I have heard not too sure on the higher pH and GH/KH as mine are in the low range.
They do poop quite a bit if you get a few too many. I throw my extras into a snail bucket/tank/vase depending what the situation is with the extra plants, more plants will change to larger container. Pond snails are great cleaners. RH just are cool, especially the colors more unique colors. I have all kinds.