I've only hacked a few things, and by hacked, I mean poof in items with a powersave. I can't actually edit my map, villagers, or anything like that. I've never used it for bells, meow coupons, or anything, because I really enjoy earning my own stuff. Sometimes I'll clone items for people, like my endless fruit baskets, gold tools and ABDs, but that's pretty much the extent of my hacking. Cloning and warping items in.
I used my powersave for some blue roses, but that was before I knew powersaved flowers could never breed hybrids. After I learned that, I got rid of all of them and bred legitimate ones. Now ALL my flowers are legit.
I don't typically poof in items or clone for myself though. Usually just for friends. Hacking only takes away as much as you allow it to. I don't allow it to take any of the fun and challenge away from me.
IF I could/knew how to hack and edit my map, I'd change my police station to the other type. Either that or totally get rid of it. And perhaps, move 1 pesky rock right in front of my house. But all in all, not that big of a deal to live with. xD