enough to notice it while sprinting at 20-25mph around the city?

you'll notice flex more at 0mph then 25.
If you have a threaded stem there is probably more flex there then in the bars.

depends on how much you weigh I can make em flex the heat treated ones are also stronger didn't you see th thread about the guy with the rb's that broke at tthe stem I bet they weren't heat treated just get some steel wool and naval jelly and polish trust me it looks nice and the added durability helps
or you could get a set of deda velocitas unless you run threaded stems

99% of the people using "drops" will have their hands next to the stem.

i clock in at about 155-160lb. so i don't think flex should be too much of a problem for me, i could easily see a 200+ guy having that problem but if i ever weigh that much, it'll probably mean i haven't touched a bicycle in months/years.

yeah thanks I weight 220 but I am an ogre so who cares

haha don't take it personally, i'm not that tall either so 200+ for me would either mean gaining 6-8 inches or getting hell of a beer belly.

me has both

Ive ran both. The AAs dont seem to flex much at all. The heat treating helps that a lot im guessing... because my risers arent heat treated and flex way more.