Glocks are heavy? Hm, if you think that, then your choices are limited.
If a Glock is too heavy, then maybe a Kahr Polymer 9mm or a Kel Tec 9mm (mine has been %100 reliable) or a snubby .38.
Anyway, I am a huge Glock fan, but it must be said that most modern designed, quality firearms, are very reliable. Glock may have lead the wave of reliable autos, but it is not alone any more. When Glock came out, most cops only carried revolvers because the option was a notoriously unreliable auto which shall remain nameless. Reliability is why cops carried a revolver for all the years up until the Glock, and why they laughed at anyone that would carry a semi auto "jammamatic" that might fail at the worst time. Anyway, the Glock was introduced to Police (who universally chose it to replace their revolvers because it is so reliable) as well as world military in the late 1980's and it's extreme durability as well as reliability in all conditions carved a path for semi autos. Since then, many makers have started making more reliable autos. People will argue with me, no doubt, about the last part that I just said, but the point is, that since that time there have been a large number of reliable autos put onto the market. From HK to Sig to Glock, and some others, there are many that are extremely reliable.
Recent gov't tests did show the Glock to be by far the most reliable of many modern guns tested, but in a few other tests, the other guns (Sigs and HKS among others) were shown to be just as reliable. In the end, unless you get a lemon, they are all reliable.
As to why the Glock is reliable, I will leave that to others to go into, but part of it is the simplicity of the design. Some people may say that they have a loose chamber that makes them feed better, but that is incorrect if you account for the fully supported 9mm, which is arguably the most durable and reliable of all of them.
All my Glocks, (the .45's I shoot the most these days) have been %100 reliable. But, so have my Sigs and HK's. I only have had one kind of gun has not been reliable in all the guns I have owned, and that has been a few really nice expensive 1911's. All the rest of my quality guns have been %100 reliable.
So, it is not true anymore that Glock has the only reliable guns on the market. But, it is arguable that it might be the most reliable gun in all conditions, there are other very reliable guns out there as well.
If you want a gun for backpacking, and want something light and durable I would think Glock would be number one. The only gun on the market that can hang with a Glock in real durability might be an HK USP but they are larger, and, my HK USP rusts! (I don't care what HK says about their "Harsh Conditions" coating, my USP rusts even though it is well taken care of). In my experience and in tests shown, you are correct that if you want a gun you can get dirty, wet, muddy, cold etc and it will still shoot, then go with a Glock.
I would personally suggest a Glock 32 in .357 Sig for your use, because for the small package it is extremely accurate (in the wild, you may need to take longer shots) and it packs a whole lot of power in the small package.
[This message has been edited by Red Bull (edited October 31, 2000).]