.....the iRiver H120 or H140? That's getting mighty old and, since it's a hard drive in there, I would think it's going to get unreliable sooner rather than later. Also you have to install Rockbox to keep it from clicking in the recording.
For someone new to recording, you want something that doesn't need to be tweaked or pampered...
OK, it's up to the OP to size up his own skills. Top up $25 and one working hour, and you can have the iriver CF modded with 8GB flash memory. Most units for sale these days are rockboxed anyway, and even if they aren't, it's no biggie to install it yourself.
I'm not saying that M10 is a bad recorder. In most ways, it's totally superior to Iriver.
But for open taping, access to the SDB and $350 on your hands, I still concur that you can get better pulls with open mics and matrix ability.
If the OP is willing to do the extra legwork...