I’ve had the system for close to two years. I don’t think you can get any better for the money in terms of durability and versatility. The system comes with a green patrol bag, a black cold weather bag, a Goretex bivi, and a stuff sack.
The price you pay is the weight and size, most of which comes from the black cold weather bag. I usually use the bivi and green patrol bag, unless I’m going out in winter conditions. (I live in NY) I’m not sure exactly what the temperature is like in the UK, but where I am it works great. If you are carrying just the bivi and patrol bag, they can both fit into a medium stuff sack, such as Sea to Summit. I carry the bag inside the bivi, just in case I get wet.
It’s a no nonsense system. It is designed for utility, not comfort. The two bags and the bivi not only fit together, they have attachment points, so they will not slide around on you during the night. The bags are surprisingly warm, even when damp. Both bags have draft tubes around the zippers, and the black bag has an additional one by the neck. The bivi is very simple, no mosquito nets, bars, etc, but will keep you dry. It’s made out of heavy Goretex, so it will not rip. I’ve used it in heavy rain without any problem.
Because of the versatility it’s the only sleeping system I use. You can find a combination for any temperature. When buying however, make sure that each item has a serial number on it.
If it does not, then it is a cheap knockoff. There are plenty of those around for a lot less. The genuine ones cost about $250-$300.
Pros: great versatility, reasonable price and very durable.
Cons: it is heavy and bulky when compared to down bags, but comparable to synthetic bags of the same price range.
Buy/Don’t buy: Buy