I don't know about the new solvents, but I don't mind running long, high ink load jobs anymore. With our JV3, which was a stronger solvent machine, I loathed running those types of prints because even with our air extraction fans running the shop would still smell up. And as the machine got up there in age I didn't trust letting it run overnight so the printing had to be done during shop hours. That isn't a problem with the HP, true there is a smell to the machine, and healthy or not like the solvents, I only notice it when I am hovering over the printer checking on the print.
Power and heat, we haven't noticed a jump in either. Our shop has 12'-14' ceiling so that probably helps on the heat side, but like with the smell, even when I am directly in front of the printer I don't notice an immediate spike in air temp. Power wise, 220 doesn't immediately mean you are drawing more power, its just spreading out the power draw between more wire so that you are not pulling as many amps through the circuit.
The biggest drawback I see is probably the speed of the printer. But when you consider that you can pull a print off of the print and immediately laminate it, without letting it outgas it does help make up for some of that. Same argument some people make for the HP not having a built in cutter. Get the print out of the printer and let it do its job, saving the cutting for a plotter. And no, you don't have to do a calibration EVERY time you change media, I don't.
I ran a JV3 for nine years, loved the machine, hated the smell. Before we started looking I said I would just buy a JV33 without shopping around, but I didn't. Wasn't impressed with the samples we got from the JV33, so I chopped it off of our list. Then I looked at the Epson GS6000. Heard a lot of complaints about things, and honestly it looks like a lot of those could of been installation mistakes. At the time though it was enough to rule it out. So I was looking at the Seiko and eventually the HP. And you know what we bought.
For anyone who has dealt with the odor and outgassing with solvents, the HP offered and alternative that fixed both of those issues. It just depends if you can deal with the "quirks", and for us, right now, I'ld buy another HP without checking out other printers, its impressed me that much.
For ink cost, did a 57"x46" banner, 13oz, moderately heavy ink load and the printer is telling me it cost me $9.39, that is for ink and media.