Been meaning to repond to this query for a while, and keep putting it off.
The Newbeam is a very nice upgrade. As indicated, it isn't exactly brighter than the original bulb, but it is much more usable IMO. It gives a broad, even, fairly white beam and runs flat regulated for about 10 hrs I recall. While upgrading my Minimag, I would also upgrade to a glass lens and a Kroll tailcap switch. Worth it? Yes!
However...
As much as I really like the Newbeam, I fell in love with the sandwich upgrades that Wayne produces. While you don't get the 10 hr runtime, after seeing that bright white light with decent beam come out of your Minimag, you'll have a hard time paying a similar amount for the Newbeam (assuming one of Wayne's lower end sandwiches). Not only that, but if you get one that is adjustable, you can pick your own tradeoff.
Double however...
For the price of Wayne's sandwiches, you could just buy yourself a Streamlight Jr Luxeon. You get the light, the LED, the tailcap. Not only that, but it sounds like the tailcap is physically better than the Kroll. And everything was designed to work together so it should be more robust. The only downside is I think it still has a lexan lens.
Man, it's a great time to be a flashaholic!
-john