I have a 5mw green laser mounted on my dob (bought the mount with the pointer) and it's the best. No more bending over for extended peering through the finderscope getting a crick in my neck. I point the scope in the direction of where I need to be using the laser as a guide, and then bend down to do the "fine tuning" through the finderscope. Saves my back and neck no end. It has a "constant on" rather than a "momentary on" switch, which works well as a mounted pointer. If you want to use it as a hand held pointer you should only get one with a "momentary on" switch. That's the safest, so if you drop the pointer, it switches off immediately.
I have another one for pointing out constellations, etc, to other folks and that stays warm in my pocket. I haven't had a fading power problem with the mounted one, but it isn't used a lot or for a long time.
Cheers,
HilB...
