Not all tubes are like other tubes, I've purchased cheap tubes thinking the same thing until I found out several things, one is the presta values are cheap and the stem thing won't last, second is the stem junction at the tube is weak and I've seen them rupture apart at high pressure and tear off with ease, so no, not all tubes are the same. By the way, Slime tubes were the WORSE!! Followed by SunLite pieces of trash...hmmm, I can't really decide which of those two were the worse, then another bad tube is Pyramid, Bell, and Q Tubes, and a lot of generic named Chinese made tubes.
One person said that they had heard that Specialized made crappy tubes, not true, I've used that brand for years and never had a problem with a bad tube except once when a seam came apart the first time I put air in it, but the place I bought it from replaced it. If you stick with the major brands of tubes than you should be ok, tubes like Specialized, Michelin, Vittoria, Challenger, Continental, Schwalbe, maybe Kenda, (I've heard good things about Kenda recently, but years back they weren't very good, so not sure personally about the newest crop). But if you stick with the major brands of tubes, you won't go wrong, just buy the brand that offers the best sale price because within those brands I listed as being good there can't be more than 1% difference separating any of them from another, though some people think that Michelin and Continental are the absolute best, but I haven't found any difference to quantify that statement.
