While I haven't run any of the newest models of Epson's solvent printers, I've been running the older models for years. The short version of my response is: I wouldn't recommend it.
Which particular models? The ones which just run CMYK, or the ones with extra colours (like GS6000 or S70670)?
While it's true that there is better physical durability with solvent inks (on most substrates, you'll damage the substrate before the ink layer), the materials available that you can print on are extremely limited, and to the best of my knowledge, none of them are archival. Papers made for aqueous printing (especially all those lovely photographic papers) are almost universally unusable with solvent inks. I'm not talking "they don't print great", I mean "my printer is an ungodly mess that is going to take hours to clean".
Obviously you wouldn't be printing on the same thing as aqueous printers. But you don't need a choice of hundreds of media - you need a few quality ones that do the job. A canvas, a matte, a satin, a glossy and possibly a high-gloss film.
What do you mean by 'archival'? I would define that as a print that doesn't noticeably change its appearance for as long as possible (some aqueous ink/paper combinations are still going strong at 200Mlux-hours over at Aardenburg) on a substrate and ink layer that won't noticeably degrade during that time (e.g. ink-receptive layers that start to flake off), and preferably as physically durable as possible. From that perspective, mounting to Dibond and sealing (for example) is good - even though it's irreversible, it makes the final product much more durable than the print on its own, able to hold together long after a standalone paper may have become brittle and fallen apart or the inkjet layer flaked off. The whole thing becomes the final, 'archival' product, not just the piece of paper holding the ink.
That said, Breathing Color's Urth has been rated as an an 'archival' canvas, available in both gloss and satin. So are Breathing Color's Solvent Smooth and Solvent Textured papers (spray on Timeless to control the gloss if you want a satin or high-gloss rather than matte finish). And I'd imagine a smooth, OBA-free, solvent-receptive polyester film (similar in appearance to Fujiflex) isn't going to degrade any time soon. Any ideas on who makes such a film?
As far as colorfastness and ink permanence goes, with the Epson inks you're looking at six months unlaminated (and that's an adhesive vinyl laminate, not a spray-on). As for laminated prints, sure, they'll have fairly stable color for several years, but after that they'll degrade fairly quickly.
I'll assume that's outdoor rather than indoor? Although the mentioned lifespan is 2-3 years.
What do you mean that they'll 'degrade fairly quickly'? As in, they'll be fine for six months-three years, then just fall apart, more quickly than aqueous prints under the same conditions?
Sure, any print will degrade eventually - but, if it will significantly outlast an aqueous print under th same conditions, that can only be a good thing, can't it?
I'm just worried about metamerism and different appearances under different lighting conditions.
Simply put, these printers/inks are not designed for fine-art. They are signage and graphics printers. Unless something has changed with the latest versions, they don't even come with a RGB print driver. They require a RIP and CMYK+ profiling workflow (and profiling is a whole lot more involved).
Certainly true of the Rolands, Mimakis and other 4-colour (or 4+white/metallic) printers. Quite a few specialist photo printers seem to be using Epson GS6000 or S70670 printers to do canvas these days, though - I wonder if they're on to something.