MTFD17,
I think the reliability issue is not as much a problem as you might think. Any incandescent bulb (even Surefires) can and may blow prematurely. With the Mag 6D bulb in the 2C conversion the chances of frying the bulb early are very low. IMHO you will be more likely to see an early failure due to dropping the light than to the filament burning out prematurely. Of course the Maglite can still hold a spare bulb in the bottom anyway so you can cover yourself to some extent from failure.
I know I will be flamed for this but even though I own quite a few Surefires I think that I would be loathed to take anything more expensive than a G2 or G2z with me to work. Doing the job we do, I have found acidental loss or damage to be a very real possibility. Yes I know some guys will justify carrying expensive lights as EDC's but then thats there choice. For my money and IMHO you can either spend a lot on a more capable light or use a cheap Mag conversion but if you do loose a Mag you wont miss it nearly so much as a Surefire!
Also do remember that your stated use was simply to find House numbers or names and I can assure you that the Mag conversion will really surprise you!
Doug