I think something the casts light to the sides as well as the front is a better bet for being seen at twilight from all angles and side streets. I opted for this one. It's a very bright piercing flash, so I think it does the job. I only use it on flashing mode, and I went through a set of batteries in a month.
Oil is good, grease is better.
2007 Peter Mooney w/S&S couplers/Terry Butterfly
1993 Bridgestone MB-3/Avocet O2 Air 40W
1980 Columbus Frame with 1970 Campy parts
1954 Raleigh 3-speed/Brooks B72