Wayne,
The Longlife bags are more economical if you are creating larger chips, shavings and debris - using the Planer, larger Routers, or lots of general shop clean-up.
With general sanding, sawing, etc., I think you'd find the paper bags would last a long time. Also, the configuration of the bag (square/rectangular) rather than those that wrap around the side of the vac, means you get the full stated capacity of the bag.
Frank does have a convenience point though.
I appreciate the fact that there is no dust when getting rid of tne paper bags - the bags even have a cap to ensure that!
My suggestion would be to see how the paper filter works for you and if it's not meeting your expectations, get the Longlife bag.
Bob