Eventually the O rings need replacing. They can break down a bit over time and pinch and leak. But I'm talking a couple of years and/or several hundred dives. Those SiTech rings are one of the lesser maintenance parts of my kit. I put just the tiniest bit of silicone on the O rings (none of that nasty licking maneuver) about once every six months, and that makes the rings go on and off easier.i have been told that using the ones with ring always ends up leaking, is that true?
The gloves themselves can develop leeks. I find pinhole leeks by filling the gloves with water and looking for the leek. The hole is easily repaired with a spot of Aqua Seal.
I carry extra gloves and liners to every dive. I also use two different sizes of gloves depending on the season and the thickness of the liners, which I change in the winter. I can swap the gloves in the rings in about 30 seconds per glove.
There are different colors of gloves around, including black. But the blue color is very easy to see by the buddy for hand signals.