I have a 4D Toplight that I moved from the rack to a special bracket that allowed it to mount to the seat post (at the binder bolt). I like the clunkiness of it and how it isn't a "quick release" and uses good old AA's.

That being said, I was wondering if there are any other lights of similar concept but with either slightly more output or possibly a blink mode? I'm sure Cateye probably has something, but don't know if it would be considered superior to the 4D.

Okay, does anyone have any experience with Cateye's TL-LD570-R? I like that it has the multiple blink modes (that modulating one is the best, IMO), but not sure how it would stack up to the 4D.

Yeah, I have that light. I got it because, at the time, it was the only light I could get my hands on (as in look/feel in store vs. online) that seemed appropriate in size to be mounted on a rear rack. I have a tubus rack that it's mounted on, and it comes with all the hardware you'd need for rack or post mounting. Overall I am happy with it. When I first got it...it frustrated the hell out of me. They have an "auto-on" and a standard version of this light. I got the "auto-on" version and it has a light sensor which, for me, does not turn on soon enough. I like the light to be on if it's raining/foggy, but if it's daytime usually there's still enough light out that the light won't trigger on. Even near the sunrise/sunset hours when you'd like to have it on, the sensor doesn't seem to turn the light on until it's pretty dark out. To remedy this, I opened the case and put some electrical tape over the light sensor. Now it just turns on/off when I push the button instead of waiting for it to get dark enough. In hindsight I would've just gotten the non "auto-on" model. The auto on feature, in my opinion, would be great if it the light sensor were a bit more...sensitive. In terms of brightness I have read some reviews that some people are not satisfied with the light output. I'll admit that it's certainly not the brightest rear light you can buy (PB Superflash is easily brighter), but as a rack light it fits the bill and I really like that it doubles as a large reflector when it's not turned on. I parked my bike about a quarter mile down a bike path near my home one night just to get an idea of how bright it really looks at a distance; for me it's plenty good enough. I haven't used the 4D so I can't compare it but a friend of mine has the 4D and just looking at it, I feel light the Cateye is brighter, also it has cool flash patterns.

Bottom line, I do like the Cateye light but if I were to buy all over again I'd just get the non "auto-on" model.

I have seen that cateye, and I was impressed enough to ask about it. I haven't really needed to replace any lights, but that light is pretty high on my list

I suppose you are asking about battery only lights , lots of those have seat post mounts ,
the latest Cat eye, that 570, is easy to remove Which is good/bad, depending on whether you remember to take it off,
or someone else does, if you forget. the QR fitting is square ,
and so the light can fit vertical or horizontal ..

my conversion was to Dyno hubs ..

B&M Toplight Line Plus is what My last 2 purchases were , the fresnel lens over the 2 LEDs have
a bright red line lit, and also have the rest of the reflector surface lit Up.

it is wired to the headlight, and the headlight to the Dyno hub. there is also a brake light version .
the dyno power pulse's frequencies, slow down and the light gets brighter.

but they both have a stand light Capacitor.

The 4D senso Plus , if in senso Mode comes on when you start moving, and stays on when you stop,
but it relies on 2 AA batteries to stay on then , shuts off by itself when stopped for a couple_5 minutes

but the dynamo powers it in what was the off switch position , on its battery only 4D senso, predecessor


on My Brompton, I have a Bontrager blinky battery light on the top of the seat post, and the line + at the bottom
where the reflector was..

upfront the dynamo light is under the frontbag , and a superflash Up on the (M) handlebar.