Heineken kegs hold up pretty well, certainly they'll last 30 days or so. They are sealed, and remain sealed, with a spout at the top. I have a bit of problem with too much head when starting to use them but that is poor pouring technique. I just checked my keg and couldn't see anything about brewing location. I always assumed the stubbies are brewed in Oz.
The lowenbrau keg on the other hand, is a different beast. It typical german efficiency, or perhaps German deference to purity, the keg has a difference mechanism. A tap at the bottom, usage involves deploying the tap and drinking, until the pressure is depleted i.e. a vacuum has formed with the removed beer and atmospheric pressure prevents beer from flowing. At this point you push it a button on the top of the keg. Now the keg is unsealed and can't really be resealed. So the beer will go flat after a day or so, which means it is best drunk in one sitting. Fortunately, I like German beer and the in laws gave me a keg fridge designed for this type of keg a couple of years ago.
Nice. An ex did the remy Martin product training many years ago when working in duty free. I've always wanted to try it since then, but have never got around to it. I was one the keating surfing scholarship at that stage and remy was a bit out of my price range.