I am interested as well. I did see some recent posts but the results from the LED path did not seem promising. I am not sure if the 05 housing will accommodate the new style LED. Still low on my upgrade priority list though.
I have LEDs on my 05 Elise for my low beams. Almost 3 years with them. IMO, it is an improvement over stock and visually looks better and brighter. As glb states, it does not shine as far down the road as HIDs or even the stock bulbs but I feel it shines more than enough of the road for me. It's brighter on the area that it does light up vs stock. I rarely drive on many pitch dark roads so not too much of an issue trying to see further down the road. If you drive on plenty of dark roads, I would probably not recommend LEDs but it can be done with more awareness. HIDs are probably the best, but don't go cheap quality/brand on those. I'm sure other members will chime in on a good set of HIDs.
I installed the Inokinetic lumoshid kit, not worth it IMO. Adaptor plate onto aftermarket projector didn’t fit, had to re-machine them. Projectors were also too long for the stock headlamp bucket so I had to modify the stock headlight bracket pretty heavily.
I've gotten spoiled by the OEM LEDs, like in my Audi, and hated the warm up time and bluish color of the HIDs in my Exige. I've tried at least 3 sets of older LEDs and they all sucked bad... No light down the road and just plain unusable. So I bit the bullet and tried yet another set of LEDs but this time, they actually worked, and worked better than the HIDs.
DDM Tuning Saber 50w. It took a bit of tuning (they spin in their bases and go from a nice wide pattern to shining down the road) and I had to find the right compromise. I eventually ended up with kind of a narrow band down the road and aimed my headlights a bit wider than with the HIDs. While nothing like an OEM application, but so much better that my old HIDs. I've driven my Lotus in complete dark and its easily enough and better than my old HIDs.
So IMHO, the LEDs have caught the HIDs in usable light but have a much better color, zero warm up time and hopefully they don't burn the reflective finish of the headlights, like all my aftermarket HIDs have done (esp on the top of the lamp).