There is no latency, the auto level control (ALC) works great, the data formats are all correct (as far as I can tell from use in Adobe Audition, Windows media player, Winamp, and various other wav, mp3 players and editing programs.

The noise floor on this unit is very very good and the recording quality is pristine.

I have made several recordings of just me and my Taylor guitar. The recordings were so convincing that my wife thought I was playing when I was I was simply playing back the music on my home system.

The battery life claims of 4 hours are grossly conservative. I use 2200mAhr NiMH rechargeables (that are a year old btw). I get 6 hours from these batteries. I have 2600mAhr AA's on route. I suspect that one could get as much as 7 hours of recording on a good set of NiMH rechargeables .... that should put a smile on your face.

I have recorded using both the external mic and my PA system line out with everything from the previously mentioned acoustic setting, to my entire band blaring at club levels. Everything came out sounding fantastic.

Marantz support was great and responded to my request for a firmware update in a polite and quick manner. With my update Marantz stated the following:

"Please note, we strongly recommend using Lexar and SanDisk SD and SDHC
cards with the PMD620"

I have a 4Gb SanDisk SDHC headed my way from NewEgg. We will see how it goes ;)

The ability to mount the unit on a tripod (my camera tripod) is perfect. Other recorders require an additional purchase for this.

I researched alot before making this purchase. I compared the Marantz to the Edriol 09HR, The M-Audio Microtrack II, and the Sony PCM-D50.

The Edriol had lower audio quality to my ears, and persistent quality issues with the phone jack breaking.

The M-Audio's use of a proprietary battery that must be sent back to the manufacturer to be replaced (think iPod esque) removed it from the running despite its good recording quality.

The Sony simply got disqualified because of price. If money were not of any concern, it would have won.

I paid ~$320 USD for the Marantz. In this price category, it is the best unit presently being made.