Depends on whether you're 'car-camping" or backpacking. For car camping, a brighter light would be more fun (hence the LX3.0) and size would be less of an issue. Likewise runtime, since you can always throw some extra batteries in the glove box.
For backpacking, in my experience, size is much less of an issue than weight......the M6 is heavy ...you can strap all kinds of things to your pack but it's the weight you have to live with....in my opinion LX3.0 is overkill for a camping light; better off with maybe a Trio or LX1.0.....especially if you're backpacking. The longer runtimes and adequate brightness IMHO would be superior to dazzling brightness and a short runtime.
My vote: for car-camping, the LX3.0; for backpacking, a Trio.While it is an excellent "duty light", I do not personally feel that the M6 is a great camping light.