Recommended all-in-one laser printers with duplexing

[Richard Solomon]

My old Brother MFC-8500 is on its last legs and I'm looking for a new multi-function/all-in-one for my home office. I definitely want a laser printer; also nice would be (1) flatbed and document feeder for scanner and copier; (2) duplex capability; and a faster modem for the fax. I don't need color, an answering machine or a handset. I'm considering the Brother DCP-8045D and 8065DN, and the Canon 4270. I would also like to stay less than $400 or so.
Any comments on these or other machines you would recommend (either to buy or run from) would be most appreciated!
Cheers, Richard