Another note: While I was able to print to every office printer I had previously configured and added to My Printers during my visit, the discovery tool could not see any of those printers when viewed through the company's VPN (HP's UPD had the same problem). A spokesperson from Xerox stated that the discovery tool would not work if SMTP packets are being filtered at the router. So if you're using a VPN, you may be out of luck.
Although I have no PostScript printers at home, I ran the discovery tool anyway to see what would happen. It didn't find my Lexmark all-in-one printer, but it did discover the PCL-only LaserJet 1018. However, when I tried to print to it, the print job appeared to spool from Microsoft Word but went nowhere.
According to product manager Michelon, Mobile Express can't detect whether a printer supports PostScript or not over a USB connection. "Our choice was to either not have [Mobile Express] discover locally connected USB print devices other than supported Xerox products, or discover all locally connected USB print devices," he says. Xerox chose the latter. The risk, he acknowledges, is that users will choose an unsupported device.
Xerox also confirmed that Mobile Express has an issue with printers that support Windows Graphical Device Interface. During setup, Mobile Express gives users the option to add printers that have already been installed in the Printers and Faxes control panel -- including non-PostScript devices that won't work with Mobile Express. "This has been addressed, and [an updated version] will be rolled out to the public in the near future," says Michelon.
On a more positive note, Mobile Express worked fine in my satellite office. It was able to find my LaserJet 1200, which is a PostScript printer, and I was able to print to that without problems.
HP Universal Print Driver
HP offers three variations of UPD: for HP PCL 5, PCL 6 or PostScript printers. I chose the PCL 6 version, an 18.5MB download.
UPD lets you choose between what HP calls Traditional and Dynamic modes. In the former, you choose one printer to map to and that becomes the permanent, default printer. Since that defeated the purpose of my using the driver, I chose Dynamic mode, which lets you change your printer destination with your location.
Next, UPD lets you set up your printers. It can search for HP printers by IP address, search for all available networked printers, or map to a shared printer (i.e., \EmachinesLaserJet1018).