Orly Bonder is a basecoat that is targeted at improving adherence of polish to your nails, to improve wear, and avoid polish flaking off or chipping. In my opinion if you wear polishes frequently, a basecoat is a must have, to prevent staining to your nails and improve the longevity (and often the finished look) of your nailpolishes.
If you are willing to invest in even more for the base coat, I highly recommend also getting one of those more opaque nail basecoats (like Nailtek Foundation II) which wears great under nude/french/pink colors to make any sheer polishes look more clean and even.
Orly bonder belongs in the clear-finish base coat category.
Comes in a standard size brush, relatively easy to use. You can see the basecoat is very liquidy- it's a lot of runny than most nailpolishes and a lot thinner. Which means the 18ml bottle truely lasts a long time (I've had mine for over 1 year and it's still going strong with 15% left).
The consistency means it also makes a very thin coat on the nails. Which I don't mind at all- because I hate the feeling of having a lot of layers of polishes on the nails, it sort of looks thick and unnatural.
Here's a light layer on my bare nails. My tips are naturally not as white because my nails are quite thin so they are a bit translucent. You can see Orly bonder forms a very thin looking coat on the top. It quickly dries and is not that smooth to touch (hence rubberized base coat because it dries to a finish that allows your other polishes to 'grip' on to the base coat). This is why a lot of base coats don't finish smooth- because coarse surface helps adherence of your nailpolish.
Overall 4/5.
I did find I don't have much staining (but then I don't wear very dark polishes that often). My polishes generally wear for a solid 3 days and get minor chipping/ wear by day 4, but that's mainly because of physical abrasion of my nails against other surfaces (e.g. trying to put on necklaces, accidentally bumping nails into drawers, or having my nails exposed to a lot of water with dish washing, when I wash my hair daily etc).
Can't wait to finish this bottle then I'd love to try other base coats (but I would gladly come back to this one if nothing else better surfaces).