I played with a few sheets of the Horisons Alumajet when I found a supplier in my country (South Africa). I use an Epson 9900. Some impressions:
-possible to get nice smooth image quality - using level 5, uni-directional printing.
-colours are rich, but image is somewhat subdued - it's not such a bright medium. difficult to light well, doesn't behave like paper.
-Use the Booksmart Fine Art Metal profile, Premium Luster 260, paper thickness 4, wider platen gap
-Before printing the sheets are incredibly sensitive to scratching - most of the sheets I printed had marks and blemishes visible on inspection after opening the pack. But I received sample sheets that were split off the normal packs so they were handled more than normal, I suppose.
-In loading on a 9900 it's very easy to scratch the sheets. The loading slot is narrow and if the sheet leans forward a bit and the receptive side touches the chassis of the printer you are stuffed.
-you have to help the sheet along with a little downward push when loading, otherwise it won't grab properly.
-once printed the inked surface fingerprints very easily, and takes days to "dry". never really dries properly. extremely sensitive.
-then you have to hand over to someone else to get the sheets laminated, unless you have a spray that works. I tried the Hahnemuhle Fine Art spray (same as premier art print shield, I believe) and got runs that ruined the print.
In all the whole process was too risky and too expensive for me. If you're willing to throw a lot of money at a good stock of sheets you can probably get good at it.