That's true, but here in the UK cyclones aren't really available. Or if they are, they're very well hidden.
Rob,
The standard bags for the CT22/33/midi/Mini are not designed to be re-used, though some people do empty them & tape them up (I'm not one of them). They are a paper bag outer with a paper-based inner filter liner. The bags for the CT26/36 are of an entirely different construction, though I'm not entirely sure what they are made of. I don't own a CT26/36 so have no knowledge as to whether you could cut them open to empty & then tape back up.
It also depends on what you're using it for. If you're only using it for a TS55, or a sander, then you'll probably find it takes forever to fill a bag. On the flip-side, if you're planing solid timber you can fill a bag in about 10 minutes.
My advice would be to stick with the regular bags for now, and just see how you get on. If a few months down the line you decide that you're spending a fortune using one bag a week, you can then buy the long-life. but if you buy the long-life now, and discover you're only emptying it once every 3 months, then you've already wasted your money.