After spending all the necessary time to unpack/setup this all-in-one, it did not work. It continued to diplay an error message claiming the paper feeder tray had a problem. Canon support said that error message wasn't even listed in their materials. BUT the support rep correctly identified it as a hardware defect and arranged for a replacement. They shipped me a new one, and I returned the defective one in the same box. The new one works. I have not used all of its functions. It's not the most intuitively user-friendly, but once one learns the drill, it's very easy to use (I've used print/fax so far). I was very unhappy with the d-o-a original. I wanted to ship it back to Amazon and be done. Canon's responsive support won me over. I was a diehard H-P customer before, and H-P produces excellent machines. After Biscuit, my yorkie, who goes crazy when he hears the machine's internal engine start up (he also attacks the vacuum cleaner and jumps at the electric shaver), knocked my H-P officejet 7310 over, it developed a hardware defect--claiming feeder door was open, when it was not.* That prompted me to look around. NEWSFLASH: Consumer Reports for December 2008 just rated this Canon Pixma 850#1! My star rating is based on Canon's excellent response, because I have not fully tested teh machine. Consumer Reports' rating bolsters my confidence in this item. I unconditionally recommend it. *Biscuit gets locked in a pen or otherwise restrained when he approaches the Canon.

I have had this all-in-one for several weeks and have not yet used all of its features. It is loaded with all the features I need and use frequently, however, and it has met or exceeded all my expectations.

A nice upgrade from my old HP. I appreciate the ability to feed documents for printing and faxing. Much better than having to lift the cover and risk the glass getting dirty and I love that I can scan docs to PDF. The print quality for documents and photos (on plain paper) is good. My one problem is that I can't get it to cooperate with my digital phone network. When the printer is turned on, it won't allow calls to go to voice mail.

AMEN!...Finally a printer that lives up to its name. Great everything. I haven't encountered any problems with my Canon Pixma MX850. Have it now for about 2 months and am very, very happy with it. Wouldn't trade it for anything (except a million bucks, but would still buy me another one with that million...ha,ha). Definitely would recommend this printer, especially at the price I got it at Amazon!...THANK YOU AMAZON!

I can't believe Canon put out this product. I previously owned an MP780 and printed probably close to 30K pages over 4 years before it wore out. It sure didn't owe me anything. Hence I bought the follow-on MX850. How could I go wrong? A little more speed, maybe an extra improvement here and there. Well, how wrong I was. For starters, they made a major "upgrade" to the user interface, way over-complicating it. Simple custom settings in the scanning in particular are very difficult to use, and to sequence through a basic scan now takes probably 3 - 4x the "clicks", screens, and time. If there is anywhere I can reconfigure the default settings to avoid this, I can't find it in the screens in their poor documentation.
The real kicker was the fax setup. I have a dual number line, with double ring on one of the numbers which is the fax line. The MP780 would switch on the fax machine on one ring, and over 4 years, never once missed an incoming fax. The MX850 setting minimum is two rings (WHY is one ring no longer available?), and it NEVER answers on two rings. It usually takes four. That means that I have to set the forwarding to my cell phone delay (which acts on both lines, can't get around that) to about 25 seconds, and sometimes faxes still forward to my cell because this machine ignores them. Plus it is unacceptable for my clients/prospective clients to sit there while the phone rings for 30 seconds while it forwards to my cell. I'll bet I lose business due to this. When I got Canon tech support on the line, we went round and round, with them blaming the voltage on my phone line as being the problem. When I asked them, "OK then how come YOUR previous MP780 product never missed receiving a fax on one ring over four years?" They couldn't answer that. The MX850 is a poor product with poor tech support. I am shocked that a product like this comes from Canon. I certainly DON'T recommend it. The MP780 was a great product, they should know "If it ain't broke, don't fix it." They fixed it alright, and not for the better.