I recently (3 weeks ago) got a Superflash for my roadie.

How effective has it been for you?

Seems to work out nicely, I use it on solid most times.

How visible is it? Can it be seen by others during the day? Please describe.

I mounted it in my office during lunch hour, and gave it a test. My co-workers agreed "holy crap that's bright" - this was middle of the day, bright normal lighting office. I'd think the flash mode would be best for daylight running. Having said that, I never use my lights in the daytime unless visibility starts to get bad, or there's rain.

How well does it hold it up?

Not sure, I've not had it for long enough - ridden about 180 miles with it, it's just fine so far.

Does it get affected by rain?

Not that I can tell, we had some very heavy rain recently that I rode through, it got dirty because I don't have fenders (grr that day ) but it worked just fine.

How often would I need to change the batteries?

No idea.

Where and/or how many places could it be mounted?

It came with an alternative triangle mount, but I put it on my seatpost.

What other information is there that I haven't asked about? If so, what is it?

It doesn't make toast, and it doesn't complain at me. It's bright, it works and it's incredibly good value for money ($14.95 CAD) IMO.

I don't have pics of it at all, I must get some in-action shots of me sometime.