REI is so handy for bike tourists it's pricey but you have: everything in one place, knowledgeable help (usually), decent quality and a return policy second to none. BUT their tubes are rubbish. If you get a flat with an REI tube and can't find where something went through the tire, chances are the tube is coming apart at the seams. This happened to me a couple of days ago. I fixed the leak and by next morning the tire with zero miles on it was soft again. Another leaking seam about 2" from the one I'd just fixed! I'm not the only one who thinks this if you check out the reviews of their tubes
there are a couple of dozen negative ones. I've also had the join of the valve stem and the tube leak. Completely unrepairable.
Some people find that pumps slip off the stems without threads. I took some sandpaper and roughed up the stem and that seemed to fix it.
And these tubes are not cheap.