I second the Dinotte. You're right, they are insanely bright. They're also big and heavy (relatively). If I was riding in a group (unless I was always in the rear) I'd leave the Dinotte off, and go with twin Niterider Solas (on low) mounted on my seatstays. When I'm by myself, the Dinotte is on steady, and the Solas flanking it are on one of the flash modes. I'm pretty sure I get people's attention. Never had a problem with any of them changing mode or powering off due to vibration.