Pros: This printer has had almost no jammed print jobs and I have done multiple ones that were 15,000-20,000 pages long. These were all duplex prints as well. Good printer.

Cons: The price and weight even though neither of these are real cons. Sometimes you get what you pay for and the weight comes from a sturdy design.

Pros: I have two M601s and two M603s. the M603 can use the 90X toner (high capacity). Prints fast; high volume/enterprise class.

Cons: The 90X toner lifespan isn't as good per page as the 90A (not worth the extra money). Maintenance kit for M601 is pricey, which is prolly same maintenance kit for M603. BIGGEST ISSUE: Drivers on disk had print issue (20 sec delays) with Win7 64 AND Win8.1 64 (printing 64bit from 32bit apps such as Adobe X, Office 2010). Each OS used different process. Win7 was splwow64.exe that locks it up, I forget the process for Win8. But uninstall, then DOWNLOAD from HP for a 3rd time, removing temp install files, etc., then wahlah, the kinks got ironed out. Took a while to finally get this important, basic printing issue resolved...should be way easier than it was, and had issue on two new install on two OS's. Crazy.

Other Thoughts: I've just always been partial to HP printers from the old school days when their drivers always worked better than other printer manufacturers across VPNs, etc. You might find a comparable printer that does as good of a job for less money. My old HP4200n still best, sturdiest printer in office of 15 printers with over 1,152,500 pages printed (just not quite as fast as these M600 series or (6) HP4014n's we also use.

Pros: Have not had a opportunity to see any pro's
Worked for almost 30 days
Easy install

Cons: Ran for less than a month.
HP tech support

Other Thoughts: I own 3 Lexmark Laser printers and 5 Brother Laser printers, two are color.
The Lexmark has always been the superior printers and run for years with little or NO service.
The Brothers are a great price point for medium load applications.
The HP is the most expensive printer with the worst dependability.
My past experience with HP was never good but our Copier service company talked me into another look
Should have stayed with my experience, Lexmark is the choice for any medium to heavy application..

Pros: We first ordered the 601N for our office and after seeing the speed of printing, the 601N was moved to our other office and we ordered the 603N. The delivery time was what was amazing. One day after we ordered them, we received them.

Cons: The 603 came with the regular 90A toner cartridge which seemed to go pretty quickly. We have just recently installed the 90X, so we will see how long that lasts.