The MT21a is rated at 10k cd and 260 lumens, and after a few minutes (2-3) it drops to around 180 lumens and ~ 6.9k cd.
The Vinh lights mentioned above put out WELL over the cd of the MT21a, so that part is easy to beat for throw...and with more lumens, so farther and with a fatter beam...in a smaller light.
The EA1 puts out ~ 1/3 of the MT21a's throw, so its not even close to replacing it let alone being an upgrade, unless the size is all you wanted to shrink, and 1/3 the throw is OK?
The Vinh lights tend to be balls to the wall as far as performance, so they are a LOT brighter and farther throwing, but, get hot and can't run as LONG as they are using more power to be brighter, etc. Of course, you can set them to a lower output, and still be brighter and farther throwing than the MT21a, but increase the runtime proportionally.
If you want a shorter light, you could look at CR123 sized lights too, etc....and if you went with rechargeable Li-ions, 14500 as an AA size, or, 18650 to go big....you could completely and utterly blow the MT21a out of the water as far as performance (But when you get disposables for free, who cares?)
