Geez, I was just looking at various options for upgrades and I stumble on this thread, weird!
I've tried the LED ringmarkers, and whilst they work well in the dark, in daylight they are not the best.
If I was based in the US, OSS would be a no brainer for me, however taking out my headlights and shipping them across the Atlantic leaves me overly concerned. I had considered buying second hand units and shipping them over, but the costs made this prohibitive.
I'd settled on the LUX H8 Angel Eyes, then saw the Weisslicht on JLevis site, and now to further muddy the waters, Kat brings up the Angel iBright!
I noticed the link Kat provided was headed up by Tom @EAS.
Tom provided the harness for my recent LCI rear tail light conversion, and he was great in terms of providing info about my purchase and I can only recommend his outfit.
I think my last paragraph has swayed my decision, I'll go with Tom.