Sony M10 user here. I'm still using the same recorder for 13+ years. I've used it with every variant I've thrown at it. Preamps: Grace, Aerco, Oade, Sound Devices/Shure, Cooper, and Naiant. Mics: AKG, Nakamichi, Beyerdynamic, Audio Technica, DPA, and Schoeps. The Sony M10 has been always consistently good. Trusted. Yet, those are Line-In recordings. For Mic-in, I like the Edirol R-09HR when using a battery box out front. A little more fatter sound than Sony, Roland (R05), Tascam (DR1+DR2d), and Marantz (PMD620). I'm a Tascam and Marantz fan too. Just my ears/opinion.... lol