Yup, 300-400 lumens is appropriate for most suburban/urban riding, especially if your rides are only an hour or a little longer. Most lithium ion rechargeable lights on maximum output are good for up to 90 minutes.

One advantage to lights with higher maximum output is being able to run them at lower power for longer battery life and still have enough light to see the road.

My Serfas SL-255 (255 lumens maximum) is just adequate for suburban/urban riding. As I mentioned before it's almost ideal for the local multi-use path at night because of the relatively low power and narrower beam with little spill. The MUP is quite dark with very few utility lights, mostly at least 100 yards away, so with dark adapted eyes it appears brighter than it really is.

But 255 lumens is pushing the limit of usability for suburban/urban riding. There's just enough ambient light to interfere with dark adaptation. With lots of utility lights around it's better to have more light to fill the shadows between pools of light.

And at maximum output on AA batteries it lasts only about an hour before it gradually dims with alkalines, or suddenly goes out with NiMH rechargeables. That's the disadvantage to alkaline powered lights -- the long, gradual dimming. I usually carry spare batteries, but replacements are available everywhere.

And for my rural rides I'm more comfortable with the 500 lumen maximum on the L&M Urban 500. I want to see deer and other critters long before I reach 'em, usually by watching for eyes reflecting light. The L&M beam is an appropriate shape to light the road directly in front of my wheel while also projecting far enough ahead to see animals.

But for longer rural rides I'd rather have either a backup light or one with a more powerful maximum output that can be run longer and still safely on medium or low output. I'm considering a Serfas E-Lume for that, but the models I'm looking at are $100 or higher.