I own both the duel fuel coleman stove and the duel fuel coleman lantern. I love them both. The ease of not having to make sure that I get every single drop of propane, or trying to find someone that sells propane to refill in the mountains, eases my mind on any outing.
I guess the question would be, where do you think you would be using it? I mean, I wouldn't recommend carrying a large container of white fuel in your pack. lol! However, Coleman has recently came out with more portable, plastic containers for short trips. I haven't picked up any myself, as they are about the same price as a gallon of the same fuel. In the future, I may pick up a bottle just to keep reusing the bottle from my large metal canister now.
On age...I agree with Emerald. I've also had to bust open an old fuel can from the barn to use. Even though we almost had to just pop a hole in the side before we got the lid open, it burned just as it would have when first purchased. I'm not sure about the cleanliness of the burn with regular fuel, but in an emergency, I would make due. I've seen Coleman brand equipment upkeep packs for under 10 bucks at the local Academy Store.
I thought I might also add that I wouldn't rely on the Duel fuel Lantern only for light. In an emergency blackout, I don't even use flashlights besides for light to fill up toilet tanks or anything that requires precision. I actually use battery powered Christmas lights. lol! I know, it's weird. 2 years ago after Christmas, I found 2 boxes of 10ft each battery powered LED teeny light set for a buck each. We have corner stands in the dining room. The boxes sit on the top and if lights go out, I walk over, flip switch and throw the light strands over the top of the stands to illuminate the kitchen and living room. We keep flashlights and headlights hanging on the coat rack by the door and large battery powered powered lights in the closet on the floor. In addition to those that I keep in the house (excluding my coleman duel fuels cuz i take them where i need them), I have the Coleman Backpacking Duel fuel stove, an MSR pocket Rocket that runs off canister fuel, and a single burner ozarka propane stove that I've only used twice. In my opinion, if I'm going to burn propane, it's going to be in my Buddy Heater. lol!