I've had a few pretty idle VPS under OpenVZ, and while I generally don't reach the guaranteed RAM, it bothers me that my VPS "thinks" it has more RAM than it actually does. After all, exceeding the guaranteed RAM can result in killed processes, while on the other hand it is very natural for Linux to eat as much RAM as possible! (Given these competing forces, it is surprising hosting providers don't offer the no-burstable option widely.)
Given this scenario I'd rather not have that occasional burstable RAM, and instead have Linux "see" only the guaranteed RAM. I guess I could open a support ticket and see what happens, but I wonder if there's something I can do from this end.