We imported one a month ago and have been using it daily since. For comparison, we also operate a Roland UV roll to roll, a Mimaki 6042, a Mutoh 461 and an Epson SC-F500 sublimation printer.
I can't speak for any kind of long term usage obviously but I can speak of initial impressions. We specified a 6090 bedsize version with 3 x Epson U1,1600 heads in CMYKWV.
The machine is much larger, more solid and robust than YouTube videos or pictures do it justice, it's heavy and takes 3 or 4 people to move it safely - if you need to site this particular 6090 machine definitely use a pallet truck or forklift.
I haven't got to grips completely with the expPrint software we're using yet but it installed easily enough, much easier than our Mutoh, Roland and Mimaki RIPs. The software is basic but easy enough to navigate.
We specified rigid ink as we print direct to object, mainly just CMYK, occasionally just W which is why I haven't spent a lot of time learning the software. It's solid, probably more robust and tougher than the next most solid ink we use, which is Mutoh's UH21. It's hard to scratch off, certainly much better than the Marabou inks we use on our Mimaki machine.
Print quality: we've had no real issues at all. We have had a few prints that have been missing ligaments on very fine fonts compared to printing on our Mutoh or Mimaki. But that's probably because we've been printing in 720 on the RefineColor rather than using vectors that we use on our other machines. Other than that, there's no real difference as far as we can see, other than standard profiling.
Maintenance: we're meticulous about TPM, every machine we use has a start of day and end of day routine. For the RefineColor machine at the start of day we run a cleaning cycle, then a nozzle print, then print a colorflag, we haven't had any issues yet but when we do (and we will) we'll do a manual head clean followed by a recharge and take it from there. The end of day involves manually cleaning around the heads using cleaning solution, cleaning the capping stations with a separate swab for each, swab the wiper and thoroughly clean the capping area.
Servicing: we thoroughly expect to have to replace everything: main board, sub boards, capping stations, heads, motors, reference ribbon, pulleys, etc. I think you have to expect that when you buy one of these machines. Refinecolor have clearly designed the machine with this in mind: everything is ready to access and replace, the machine comes with spare capping stations, head ribbons, etc. By comparison, the Mutoh and Mimaki machines are more complex and fiddly.
Would I buy another? Right now, yes is the short answer, will I say the same in 12 or 24 months? We'll see.