Let me jump in here on a couple of points, putting several things together.
[***I still don't see the QUOTE function on my browers -- MARK S., can you email me privately to discuss? I don't want to take up list time with my stupidity]
On the piezo/thermal/heads question: Quentin, I disagree with you on most of your points.
-- It's an urban legend (which I have also promoted) that thermal heats the ink droplets; it doesn't.
-- HP has ink encapsulation.
-- The user-replacability of the printheads is a good thing, not a problem in my view. In reality, the heads will last a long, long time (based on total ink throughput), but at least you have the option to replace them, if you want. Same with Canon. Not with Epson without either a BIG cost or throwing the printer away.
-- Adding the spectro function to the Z3100 has nothing to do with any percieved printhead problems (I have discussed this at length with HP).
Let's just agree to disagree, OK?
On the dry-down/stabilization, all this is user controllable. You can lengthen/shorten the dry-down time. On dry-down for calibration/profiling, HP has determined that 5 mins is all that's required for their inks and calib/profiling protocols. Stephen: I haven't seen smearing or bleeding on my Z3100, which I only recently installed. (FYI, measurement time is adaptive to the density of the measured colors; more time for measuring dark than light colors. HP does not average multiple measurements per patch since the printed colors are very uniform, hence, no need. The in-the-box profiling function reads just under 500 patches for profiles (+ 160 for calibration), but it's open-ended and you can tie into any target size or type you want, up to 7,000 patches if feel like it. Only takes more paper and time, and I think the Advanced Profiling Solution option.
On the issue of calibration in general and Epson ColorBase in particular, now this is an interesting point. Epson has all along communicated that the pro printers are "factory calibrated" and you don't have to worry about it after that. How many times have you printed in a factory, especially theirs? ;-) Seriously, it's fairly apparent to me that all printers change over time. Parts wear, the printing environment changes, etc. Let me say right here that I know very little about ColorBase (in fact, if you search on Epson sites for it, you get nothing). Apparently, it's a software solution that helps you -- DUH -- calibrate your printer! (someone please correct me if I'm wrong) HP has been offering this since 2004 starting with the DJ130. Maybe Epson is finally realizing that they need to change their tune on this point? I dunno, just theorizing. And where is Canon on this?
All for now. Gotta install a new dishwasher.