i am pretty much the same as you, not a lot of after dark riding or commuting here.so i don't do much after dark riding, mostly like you said, a few casual dusk/evening jaunts.

although i now want to ride most of the manhattan greenways at night and then take detours into the city itself. in my situationat least, for the greenways the 1w is still fine. for the city, i dont even need the 1w for light but just to flash so people can see me, as the city is well-lit. it's to be seen.

but yeah, you HAVE TO GET A taillight. when i have my superflash on suburban roads, cars coming behind me give me a nice WIIIIIIIIIIIIIIIIDE berth. that thing works well. for the city i bought another $10 cateye red taillight and clip it to my rear collar or backpack.

oh and with reflection. i guess it depends where you are but i dont think a reflective vest is mandatory. depends on your area how cars are, etc... if you are out in a very rural area where cars tear around at night, not used to bikers, or no shoulders, it might be a good idea just for that kind of night riding. for me, i just put several reflective strips on the back of my helmet. plus my saddlebag has a reflective strip, and the SF on it. nice thing about shcwalbe marathon tires is they have a reflective sidewall strip. i feel pretty good with this setup.

but visibility to vehicles is key key key.