I can't really comment on the various speed settings available from the front panel. We use a 3rd party rip which has allowed us to create our own settings for speed... For instance, the control over directions (bi or uni), number of passes, and carriage speed. These settings could be applied to profiles for various media types... A premium glossy paper might be at maximum passes and a slow carriage speed whereas a setup for crappy presentation paper might have half the passes and a much higher carriage speed.
These same controls were available to us when we had the Encad 880. The HP is in all ways providing a much superior output when you follow this path.
As for maintenance, just clean the thing on a regular basis. The machine is hardly as problematic as even the latest Encad printers (1000/1200i). No more air in the ink lines, no more priming and repriming, no more getting a cartridge replaced under warranty because it died at 100 ml of ink...