I have been using the Winkku's now for about three weeks now.
Right out of the box, the right one, in marker light mode, seemed to be a little dimmer than the left one.
In signal mode, they both worked flawlessly.
I am not generally fond of handlebar mirrors, I don't feel that convex lenses are a good idea on bike mirrors either, I do understand where it would have some benefits. I just don't like them.
I had some issues mounting them securely on my trekking bars. The trick in my case was to make sure that the plastic rectangular loop for the velcro strap, stayed on the bottom outside part of the inner curve of the bars, so that the weight of the unit wouldn't roll the unit down.
I was happy with the overall performance of the Winkku's. Last Thursday morning, I went down twice in four inches of heavy wet snow/slush. Both times it/we landed on the left side. Imagine my surprise when I discovered that the right side winkku had decided to acquire a new mode of operation: it would signal a turn when you turned on the marker light mode and it wouldn't stop until I shut down the whole unit.
I then proceeded to void my warranty (several times) trying to get it to work. It would work fine when it was disassembled, but, when I reassembled it, it wouldn't work. We played that game for awhile. I finally decided that the turn signal switch was sticking. I gave it a shot of WD40.
Seems all better now.
I feel much safer using them, to the point that I would buy another right one, or set, if I have to. I am hoping that I won't have to. They are on the list of things that would get replaced if needed, if possible. I like the fact that they mount on the handlebars far enough apart to actually be useful as turn signals.
They are a little pricey, but, I feel that they are worth it. My supervisor commented that they helped define my vehicle outline.--his words, not mine. I would recommend them to any one looking for such a item, who couldn't /wouldn't make their own.
Here is some pics of them in marker light mode from behind about 30~40 ft:
The white spot is the back of my seat.