Michael, The dn550 fulfills **all** your recommendation, not sure how much buffering there is but sure some. To start recording from cold, slide switch down and hold for a moment until you hear the sound, whereby announcement of battery status. Machine is instantly ready to record, just press button near other end on right side, you hear a short tone, recording is in progress. Supports WMA, Wav and MP3 all in various rates. I don't use mine daily or for very long times at a go, but having been to Germany this time last year, for a few days, I took two sets of batteries, it takes two AAA size, not sure if they can be charged in the unit but I suspect they can from the USB connection. When I left the UK the batteries had been in the unit for about six weeks, I did a great deal of recording whilst in Germany, probably around fifty hours, I needed to change the batteries last November. I have the same ones in now since then and having been away on a conference during 9-12 May, where I recorded well over twenty hours, the batteries stijll register high. These, however, are the very highest quality alcali dry cells I can obtain, not sure of their price, suspect around 4 quid a packet of 4. Hope this is of use for you. Colin Howard, by the Lord's providence has lived at his present address near Fareham in Southern England, since February 1992. ** To leave the list, click on the immediately-following link:- ** [mailto:access-uk-request@xxxxxxxxxxxxx?subject=unsubscribe] ** If this link doesn't work then send a message to: ** access-uk-request@xxxxxxxxxxxxx ** and in the Subject line type ** unsubscribe ** For other list commands such as vacation mode, click on the ** immediately-following link:- ** [mailto:access-uk-request@xxxxxxxxxxxxx?subject=faq] ** or send a message, to ** access-uk-request@xxxxxxxxxxxxx with the Subject:- faq