Durability is good to excellent. They use the same self adhesive vinyl for outdoor signage and vehicle signage. I've had some large vinyl letters cut on the same cutter sitting on the top of our rubbish bins for 4 years and they're still good. If it can put up with being outdoors 24 hours a day for 4 years and all the other things that bins have to put up with I'm pretty confident in its durability indoors on gently treated lab equipment. Sure, if you're rough enough it'll come off, but it's the same level of roughness that would scratch 2 part epoxy screenprinting that you'd use for a production run.
I have a theory that applying the self-adhesive vinyl to a freshly painted surface, when it's properly dry (24hrs) but still slightly 'green', improves the adhesion over applying to a fully cured (weeks) paint surface. I can't prove it without destructive testing, but it seems to work well.
I haven't felt the need to overcoat the finished things with clear lacquer but that's a possibility too - might need some experiments just to make sure that the lacquer didn't attack the vinyl or its adhesive.
The cutter I've got is a 2nd hand (isn't all my stuff) Silhouette Portrait (mark II, they're on mark III now) that I paid £50 for - which comes with its own software. The vinyl is in rolls or sheets, a 203mm x 5m roll like I use costs £8.59 and is available in every colour under the sun. I also have heat transfer vinyl for T-shirts, so I can make those too. As well as the self adhesive vinyl you need "transfer tape" which is transparent/translucent tape with a Post-It type adhesive on the back.
You cut the vinyl out in the plotter, weed it (removing all the offcuts, bits that aren't part of your design), pick it up off the backing sheet with transfer tape, put the whole thing (cut out vinyl and transfer tape) over your target surface and burnish it down. The adhesive on the vinyl is
much stronger than the one on the transfer tape, so you just peel off the transfer tape, rub down again for good measure and you're done.
Someone else's ebay photo of a Silhouette Portrait 2 and some supplies. The 13A UK plug should give some scale:
Obviously the cutter will cut other things too, including paper and cardboard. I've used it to make paper stencils for painting through. One of the things you can do is print things and then use the cutter to cut outlines around them - make your own stickers if the mood takes you. I've used it to cut mylar sheets (OHP films) to make homemade solder paste stencils from with good results. That's what I originally got it for, but it came with some scraps of vinyl and playing with those to make some small signs convinced me to get some proper stocks of vinyl and experiment. Labelling up equipment was one of those experiments and I'm satisfied with the results so far.
The only thing tricky about using it is getting the speed, pressure and depth of cut right. They're all adjustable and different materials need different settings. It matters most with things you want to only cut into, not cut the whole way through, such as cutting the self-adhesive vinyl but not its backing paper. The depth of cut also affects how tight a curve it can follow successfully (it uses a drag knife), which in turn affects how small a feature you can cut. Any text smaller than about 14pt in vinyl can be problematic. Thicker strong materials, like the 100um mylar I've used for solder paste stencils don't like small curves at all, I've stuck to rectangular stencil openings for that reason. You can cut relatively gentle curves in anything, I've cut out 75mm high letters out of quite thick card.
All in all, it has proved a very versatile and useful tool to have available.