I’ve had very few problems with any inflatable sleeping pad I’ve tested. Some have lost air, but I’ve never had one deflate completely (knock on wood). That said, there are some tricks to getting the best night’s sleep and having a pleasant trip.
Don’t inflate your pad with your mouth: For one thing, some of these pads are huge, and it’s just a pain, but also your breath is warm and moist and you’re injecting into nylon, which is a recipe for mildew and mold. This worry may be somewhat overblown—a few people have cut open pads they’ve inflated by mouth for years and found no sign of mold—but considering what a pain it is to do anyway, it seems easier to just avoid it. Most manufacturers include some kind of pump sack these days, which makes quick work of inflating your pad. There are also motorized pumps that only weigh an ounce or two, like the Flextail pump.
Don’t over-inflate: Insulated sleeping pads work by putting air and material between you and the cold ground, but that doesn’t mean you need to inflate it until it’s taut. It varies by pad. I generally find that the best method is to inflate it taut, and then start to let out air, lying down to test it until you get to where it feels comfortable. The downside to this method is that your pad isn’t that thick and you’re more likely to bottom out if you let out too much air. I find this isn’t much of an issue for stomach or back sleepers, but if you’re a side sleeper it might take some time to find the sweet spot between comfort and warmth.
Carry a patch kit: Most sleeping pads these days include a patch kit. I rarely bring these kits and instead carry a small roll of Tenacious Tape ($6), which will solve rips and tears in everything from sleeping pads to tents. Make sure to test a small piece of tape on your pad beforehand to make sure the tape sticks, and bring an alcohol wipe to clean the affected area.
Women need higher R-value pads: Women generally have lower body mass than men, which means women should add roughly 1 R-value to get the same amount of insulation in the same situation. (I also recommend upping the R-value if you’re a cold sleeper in general.)
Sleeping bag ratings assume R5 pads: Most temp ratings you see on sleeping bags are true only if you’re using a sleeping pad with an R-value of 5 or higher (they also assume you’re wearing a base layer). If your pad is less, you will need to adjust your sleeping bag temp rating accordingly. For example, using your 30 degree quilt with a R4 pad will likely leave you cold if you encounter freezing temps. In that situation you’d want to either up the R-value of the pad, or bring a warmer sleeping bag.