in a perfect world, we could get 90% of the smoothness a roller squeegee affords from properly controlling our variables. but we're not that good.
i almost feel like it's cheating, the improvements in the print quality, for the minimum of effort. right shirts, ink, settings and your top colors can look like it's printed on vinyl.
biggest hassle is that it pretty much only works when you have GOOD control of your flash. Too little flash and you'll be hitting still-wet ink. Too much flash and you've fully cured the ink and the roller ain't going to do crap. Get the ink "gelled," get it "cheesy" and hit it with the roller and you've got a nice smooth surface.
i can be recreated cheaper DIY style. Action for sure charges steeply, but it's sure nice to have it just work right out the box too. (you can use this as a lint screen as well, but we found that the DIY solutions to that were effectively free.