Is the Zoom noise problem through mic inputs or line inputs? Because it seems that the OP is going mics-->battbox-->line-in. Which might be another reason to stay with the Zoom for a while.
Regardless, I love my PCM-M10 too and it is no more difficult to use than the Zoom. The settings, if you need to change the defaults, are something you'd probably change once--I have never gone into a settings menu during a show. It's got a nice simple remote. Battery life, build quality have been praised by others. And if you're going to a show that doesn't like tapers, the PCM-M10 looks to the guards like a point-and-shoot camera, not a recorder (or electric razor), because of the recessed mics. One guard warned me not to use the flash.
OP also asked about mic placement. My first choice is generally near the soundboard, because the guys in the sound booth are probably using their own ears to gauge the mix. If you aren't stuck in a seat, though, you should use your ears. Let the opening act be your soundcheck unless you love them too. Move to various locations, close your eyes to eliminate visual cues and see what you like.
Places to usually avoid: right up close to the stage. The PA is pointing over your head, not where you can hear it, and while your mics may be able to pick up the stage monitors, the vocals you think you are hearing are probably a combination of lip-reading and your memory of the song. Also, under balconies is usually a bad spot--boosts the bass, muffles the highs.
Every room is different. If you go to a place in your hometown regularly, you should be able find its sweet spot(s) pretty soon.
And get away from people who talk because the best sounding spot in the room is bad with a conversation going there.