Scout, hands down. I had a Ranger and loved it until I had to pack it, 9ish lbs compaired to around 5 for a Scout. Unless you do a lot of heavy duty diving with lots of weights and twin tanks the Ranger is just more BC than you need. In addition, the 45lb bladder on the Ranger is way more than is needed for the vast majority of divers. I use my Scout (35lb bladder) for everything from T-shirt diving (0 weights) to a drysuit (25lbs) and for the most part the 35lb bladder is more than I need. I also have a smaller bladder I got off another Zeagle (around 18 lbs) that is most often the bladder I use so if I were ordering another Scout I would try to get one with the 25 lb bladder. The Brigade is nice but why add the extra weight (and cost) of the upgraded harness if you are traveling with it and need to conserve weight, the Scout harness is plenty durable for single tank purposes.
You might also consider the new Tech- Express from Zeagle, it is around 4.5 lbs and looks interesting, I am seriously considering one.