Here's my 2 cents. I had a Nite Rider MiNewt USB. It was good enough for seeing in dry weather, but not quite bright enough when things were wet. At the time I thought it was plenty bright enough for "being seen".

But I got a P7 flashlight (even cheaper than a Magicshine which uses the same LED) and I could instantly see a HUGE difference. People who used to pull right out in front of me as if I wasn't there now gave me plenty of time to get thru the intersection. And it's bright enough to see in wet weather. I'm very happy with my lighting set up.