Re: How to lvl new character in NG+
It's not really cheating because it's been built into the game.
There are no adverse effects except an (annoying??) Deadbeat indicator at Home.
It's basically a way of getting higher experience from low level monsters.
Personally, I didn't like the indicator so I only used it once I was at a high enough level to complete all of the (5) maps at once.
You can also use the Arena but you don't get as high experience for your kills.
If you check these threads there's discussions about it that may explain a few things for you.
viewtopic.php?f=11&t=654&hilit=deadbeatviewtopic.php?f=11&t=628&hilit=deadbeat+indicator