I've used this to record a loud rock band (mine) with an AT822 stereo microphone & the results were amazing. Only quibble.....when recording loud stuff the automatic level control is noticably audible-like over limited. Set the record levels manually & its fine, no pumping. Default setting is automatic, so you have to set it each time. Worth the trouble, sound can't be beat for a unit this size & price. Home Run, Sony!

A wonderful unit that does virtually everything mentioned in its hype, but what is NOT mentioned, at least for me, ruins an otherwise excellent piece.

To explain; the MZ-M100 really does allow up to 34 hours of recording time at it's lowest qual settings. This is incredible considering to obtain another 34 hours only would require a disk change. VERY cool and not like an IPod or other device that when it's full - it's full.

On a good day with the wind at its back, the battery in my unit seems to be good for just under 3 hours of use. Sony does include a clever 1 AA battery pack that can be strapped onto the unit and that will provide an additional hour or so of usage but you'll quickly see that potential recording time easily exceeds expected battery life. This is a problem but I suppose one could purchase extra rechargeable batteries and keep a pocket full of AA's handy.

The real problems begin AFTER you've recorded your material. The MZ-M100 ships with a fine stereo microphone so the unit must be designed to record this way and it does a fine job. There are automatic compression circuits that can be somewhat customized by the user so that the mic will not overload recording a concert and yet can be made sensitive enough to record bird calls in the woods.

OK, so we have a deck that can record 34 hours via a mic or line in. Let's say I manage to record that much material at a music festival, return home and decide to dump all that recording time onto my computer. Hmm. In the past, I'd just take the disk out of the portable unit and slap it into my home deck and SP/Diff the tracks to my computer or I could hook the portable unit up directly via SP/Diff and dump though I don't trust batteries and shun this method. Well, the MD-100M does include SP/Diff but for some reason, Sony only made this "one way". You can transfer data INTO the unit but not back out. The ONLY way to get your data off is to use the included USB cable and Sonic Stage software. This might not be so bad except that while using the USB cable, one must open a little door to plug in the connector and when you slide this door open to do so, it completely covers up the AC adapter jack! You can NOT use the AC adapter while dumping your data via USB. So, you are only able to obtain perhaps 2-3 hours of your material at a time. I could even live with this but the absolute deal breaker for me is that Sony does NOT manufacture nor has any plans to manufacture a home AC powered Minidisc machine that can accommodate the HI-MD format disks.

After calling Sony several times, it occurred to me that I thought I knew what was going on; Sony is powering the MZ-M100 via the USB buss while it's hooked up and THAT was the reason they don't want you plugging in the AC adapter while USB is active. Too bad as I was assured that the unit is NOT powered via USB while that cable is hooked up.

All this leaves me asking "why"? Why cripple an otherwise killer product in this way? Are they eliminating MD format? Is this the MD crusher? No home unit that can play or record these new Hi-MD format disks? Huh?

To me, the worst offensive item of all though has to be this; you are only allowed ONE shot at getting YOUR data off the MZ-M100. That's right. Once you've recorded something onto a disk, you have precisely ONE try at getting it off and into the Sonic Stage software. It keeps careful track of your attempts (I KNOW - I found this one out the very hard way). Since the unit is crippled power wise and they only let you try for your data once, this machine is a scary trap that will at some time or another lose recordings that you or your clients value highly. There may be a hack to allow you more than this one try, but I've not found it on the net and I've looked.

I bought into Minidisc when first announced. I still have and use my Sony MDS-101 deck, purchased a second Sony home machine that allowed one to plug in a computer keyboard to title disks, I have a Sony portable MD player (Walkman) and a Sharp portable unit that treated me very well over the years but finally gave up and had to be replaced by this MZ-100M. I have several hundred older format disks that the MZ-M100 will PLAY but won't RECORD on so my media investment is devalued. Now I consider buying into a "new" Sony MD format, Hi-MD but Sony offers me nothing except restrictions.

I believe this unit is built to compete with the other MP3 players out there, IPods, etc. For that purpose, it's a dandy machine. But used as a professional location recorder, it's crippled so badly that I can NOT recommend it. Sound qual is excellent but the designed in potential for losing valuable recordings, to me, wipes out any true value offered by the unit. Look at Edirol or M-Audio instead.