Hi jags!
In truth, dynamo lighting is in a state of flux at the moment, with a number of new, great-sounding lights just arriving on the market. The best advice I can give is to wait a couple months and then read the reviews as these things hit the market and get actual use.
That's what I plan to do.
Meantime, I will continue to use my B&M Lumotec IQ Cyo R Senso Plus Black (with less bright/better dispersion 40 lux, taller beam). It is the one that retails for USD $107.00 on Peter White's site, here:
http://www.peterwhitecycles.com/b&m-hl.asp I like the *amount* of light very much, but have also been extremely disappointed by the bright-white hotspot in the middle of the beam that mars the otherwise nice spread. When I ordered it, I *thought* I was getting the older-style reflector, but instead got the later job that results in a less ideal beam and that horrible hotspot that draws one's eyes to center on it, making the rest just so much beam-spill. Andre knows the difference, and so do I -- I rode at night through the NL's Green Heart and Hoge Veluwe next to a friend who had the old-style reflector/LED on his IQ Fly and still remember the velvety, even spread of light that was wonderful to behold. I desperately wish mine was like that; the older IQ Cyos were, till B&M changed them.
Of the three IQ Cyos SJS Cycles offer, I believe the one like I have is here:
http://www.sjscycles.co.uk/busch-and-muller-lumotec-iq-cyo-r-plus-40-lux-headlight-with-bracket-prod22818/Jags, so you'll know better what to look for, here is how the name breaks down:
B&M Lumotec IQ Cyo R Senso Plus Black means...
B&M = Busch & Müller or BUMM, maker
Lumotec = range
IQ = rear-aimed LED bounces light forward off a carefully shaped reflector
Cyo = series
R = reflectorized lens with nearfield illuminaton that starts the beam at about 1m from your front wheel. Less bright at 40lux but a closer, more even spread than the other (non "R") offering in the Cyo series.
Senso = Third position on the switch besides ON and OFF, this uses an electric eye to turn the light on/off automatically, as when entering/leaving a tunnel...or leave it on SENSO all the time and the light will turn on/off whenever it gets dark/light. Andre politely differs on the value of this feature, preferring instead to leave his on all the time for visibility. I prefer to turn mine off on long, car-free rural stretches in the desert so I can get maximum juice to charge the batteries, yet not forget the light when I need it. Just a difference in preference.
Plus = equipped with a standlight. This is a capacitor that stores electricity so the light will remain lit for up to 4 minutes or so when you are stopped, allowing you to remain visible at traffic lights or when trying to find the right key to your shed-door padlock.
Black = color. Also available in a silver/chromed case at a small upcharge if one prefers.
The "N" ("No") model you sometimes see has just the plain ON/OFF switch and no Senso (standlight) function and is a little less expensive as a result.
The model without the "R" in the name is the more powerful 60lux version that leaves a black hole in front of your wheel. It is therefore better suited for high-speed riding rather than slow or on bike paths/lanes, where you'd want to be able to see and avoid glass and debris at lower speeds.
Peter White also describes the new B&M Luxos at the same link above. It is available in two flavors, one having USB charging and a high price equivalent to a Cyo and a Tout Terrain The Plug2 combined. For no particular reason, I am deeply suspicious of the long-term life of the rechargeable battery it uses to provide charging and "panorama mode" lighting. Given what it costs, I surely hope it will be replaceable when/if it develops a "memory effect". All may indeed be well, but I wish BM had stayed with capacitors for the purpose, but understand why they could not, given the design. I will be a gentleman and let others go ahead of me in line so I can learn from their experiences before plunking down so much money when I already have something that wrorks. If it proves to be a corker in long-term use, then I can develop a case of "gottahavits".
My suggestion for you? Grab a Shimano dynohub wheel now(ish) while it is available at a good price. Get the color you want (black or silver) or it will bug you all the while you own it. Then, wait a bit till the lights sort themselves out. I realize this means you might not have a working dyno-powered light setup for awhile, but it will assure you get a great combo for the least money overall. Andre has generously offered you an older-model, non-LED light that would at least let you use the setup and would get you by for awhile til the perfect LED light shows up at a good price. If you went for the newer AXA Nano/Nano Plus model Rualexander has referenced, you would have a light and charging system all in one, catching many of the features of the new B&M Luxos for a fraction of the price. It looks nice, and the design is very clean as well. It makes a lot of sense. I haven't used or seen one myself, but it has all the needed ingredients and I trust Rualexander's firsthand experience with his AXA Nano Plus in actual use. To read more about it in his posts, go to:
http://www.thorncycles.co.uk/forums/index.php?topic=4121.msg24549#msg24549http://www.thorncycles.co.uk/forums/index.php?topic=4121.msg24605#msg24605http://www.thorncycles.co.uk/forums/index.php?topic=4121.msg27687#msg27687http://www.thorncycles.co.uk/forums/index.php?topic=5129.msg27025#msg27025I plan to read up on it a bit more myself.
I hope this helps.
All the best,
Dan.