Question 1

Will this printer take the 81X toner in addition to the 81A toner?

Accepted Answer

No it does not

Question 2

Does this machine do auto 2 sides?
How decent is the envelope feeder on this machine?

Accepted Answer

This exact model (M604n) does not have a duplexer (2 sided printing) and the bypass tray can be used for envelopes, but if you plan to print very many envelopes (more than 25 per day), my advice would be to purchase HP part # F2G74A (HP LaserJet 75-sheet Envelope Feeder).  If you want to add duplex printing to this model, you will need HP part # F2G69A (HP LaserJet Automatic Duplexer for Two-sided Printing Accessory).  Or you can just purchase the HP LaserJet Enterprise M604dn (HP Part #E6B68A), which comes with duplex printing feature.

Questions & Answers