What handlebars for my commute?

People seem to complain that 15 / 20 miles is the max they can do with risers/flats.
Good to know that 20 is not the maximum mileage with risers. I will probably go for some flats or risers in the not too distant future.

I've ridden over 20 miles in one hit on several occasions, and on a few occasions over 40 miles, all on risers, a couple on flats, both pretty comfortable, the one thing I did notice is though once you are doing more than 15 miles in one hit padded cycling shorts are a very good idea, anything over 20 miles and my arse was definitely feeling it the next day.
What i'm trying to say is, your milage is pretty miniscule, its not going to make a great difference to your comfort what bars you go for, I like risers and flats, its personal preference, it'll come down to "feel" more than anything, and what "feels" better for you.
On one of the 40 mile-ish rides a lot of the roads weren't exactly smooth, my arse was sore as fuck the next day for a few days, not pleasant, no chafing or anything, just felt really bruised, may have also been due to the shit saddle, these days I have a rather nice Fizik which feels damn comfy :)