I think I was the first to offer extremely overdriven DirectDrive lights for general sale.
To date no LGIs, Classic, Super, or otherwise, have come back to roost because of burned out Luxeons (and we're talking over 600 units during a most exciting two year span).
The Space Needle was simply an evolution of that all-risks-be-damned concept, and although about three (yes, 3 total) have indeed "burned out", it was a mistake on my part for pushing the boundaries and risking "T" Vf-binned Lux 5s in them, after which I only used "U" and deeper-into-the-alphabet (higher Vf) bin codes.
If you are looking for forever durability, then drive them at spec or even underdrive them. You will fall asleep while getting just acceptable light levels, and yet nothing really "wow" will jump out at you unless you stick it in a big reflector (for example a Lux3 driven at ~700mA in a big Maglite will throw nearly as far as a direct driven one, but again this is a function of the reflector size).
BUT - if you are looking to show that LEDs are indeed knocking on the proverbial incandescent door, or would like a crowd to gather round seeking the source of that super-white alien-like beam reaching up into the sky, or wish to drive a solid-state light at virtually 100% efficiency, look no further than a Direct Drive Luxeon light to get you there.
AND - if you think of this as a way to push the envelope in LED development, then the Very occasional "bulb changes" involving desoldering/resoldering two wires is simply a small collateral cost for the pleasure of participating in leading-edge lighting development, the first real advance in portable lighting since Thomas Edison first literally burned a sliver of bamboo used as his bulb filament - and then it almost even begins to make just a little sense... /ubbthreads/images/graemlins/naughty.gif
You only live once, so ignore the sphincter-squeezers and BUILD that Space Needle. You will never regret it.
(but use 30- or even 32-gauge wire...) /ubbthreads/images/graemlins/grinser2.gif