I have one BLT Rear Super Doppler DX too, which I think is indeed the same as the Serfas TL-1000. I believe it's a good taillight and has a few good points, but also serious limitations :

– Basically, the Super Doppler is a red headlight.

– It's a few times brighter than the Superflash exactly on axis, and probably similar to the Superflash all around. The Superflash is brighter than the Super Doppler at about 10-15° off axis, which means that the Superflash would be better in an urban environment, whereas the Super Doppler would be better on a highway. On a highway, having a long rear-facing "beam" for long-distance visibility and some sideways visibility is probably the best combo.

– The flashing mode is a standard one. I don't use it in flashing mode at night (way too powerful so it's annoying). But on a foggy day, I think the Superflash "strange" flash pattern is more attention-grabbing.

– The Super Doppler uses 3 AAA batteries, and the way its voltage "regulation" is done, it dims very rapidly. With disposable batteries, I would say that within about 10-15 hours it is no brighter than the Superflash. And with rechargeables, think about recharging them every 4-5 hours, and try to cycle two sets of batteries because most chargers charge batteries in pairs.

– The bracket and shape of the Super Doppler limits severely mounting options. Except with severe tinkering, it can be mounted on the seatpost, and that's it! (ref. this photo).
The bracket can be adjusted up and down at the screw; there are notches that are not precise enough, considering the narrowness of the beam. On my bike, at one notch, it's aimed about 2° below horizon, and at the next one, it's aimed 1-2° above.
The U-shaped holder can be adjusted by about 10 degrees left and right. So you bolt it in place and aim it more precisely afterwards. Great idea.

– Because of its shape, it cannot be mounted on a rear rack. Or at the very least, I have yet to find a reliable way.

– The bracket looks flimsy. I haven't broken mine yet, however I use that light only for nighttime excursions.


My conclusion
All in all, I thought the BLT Super Doppler was a great taillight for highway use, but the fact it cannot be mounted behind a rear rack limits its usefulness:
– I can't use it when I carry too much stuff on top of my rear rack, which happens about 2-3 times a month;
– I can't use it on the tandem nor on the trailercycle, because the stoker saddle is too low so the light would be hidden by the rear rack;
– I can't mount it on the trailer;
– Battery charging needs some serious planning.



To reply to Freako:
How could the SuperDoppler have just a narrow beam?

Basically, the light is translucent and the cap is transparent, but the three LEDS are directional ones (look at this photo carefully).
This thread (2nd vs 3rd photo) shows you that it's very bright on axis because you're right in the direction of the beam, whereas you only see very bright plastic when you look at it sideways. It's visible in a 180° cone, i.e. left and right, up and down. The up and down visibility is not a problem for a taillight, but is a serious one for the BLT headlight which is designed in the same housing (Super Doppler DX).


Comparing the Dinotte to the SuperDoppler

Although I don't have the Dinotte, it's easy to see from the photos that the Dinotte is brighter. But from their website, the Dinotte has an opaque housing, which means it throws absolutely no light sideways. Considering its brightness, I would suggest the Dinotte is good either on highways on in places where there is a lot of other distractive lights. But don't ride in groups with it, unless you are at the end of the line!