In reply to muriqui: I had a the buffalo special six shirt and buffalo trousers. Plus a waterproof hat and gaiters. I wore that combination through two whole scottish summers and winters and my ML assessment. In the summer I wore a thin baselayer on top and kept the shirt in my rucksack. Hill-days and multi-day expeds.
I never carried a waterproof, except for a handful of times on particularly cold winter days when I kept one in my rucksack to throw on over the top on lunch stops. I'd just let myself get wet - it didn't matter! The whole system would dry off really quickly too when it stopped raining, particularly if it was sunny. I could go from saturated to bone dry in a couple of hours. But like I said - it didn't matter if I was wet, that's the beauty of it - you're always comfortable. Even when you're wet, you don't 'feel' wet. Don't know why, you just have to experience it. And remember, 'wet' means your sweat too.
Temperature-wise it's very versatile because of the side vents. More than most people seem to give it credit for, in my opinion. I always wore it next to the skin, except if I threw it on in summer if it was chilly, over the top of my baselayer.
Plus, if you're a paddler I always wore it under my dry-cag and used the trousers too. A shortie wetsuit under everything else.
Gorge-walking too, sailing, caving, the list goes on. The most versatile kit I've ever owned.
My shirt almost wore out after about 6 years of hard use. However, it was still going and donated it to a friend of mine as a leaving present (he was a paddler). I still have the trousers and they're a bit of a sorry sight (but still usable) and feel a touch too small for me now.