I guess it depends on what you mean by action (today happens to be our anniversary and there's probably a joke implied but we won't go there...) I know when I'm home I can go sit in the back yard and within ten minutes (usually sooner) a hummer will visit the feeder but lots of people have more than one feeder with many hummingbirds hanging around all the time so, of course, it's all relative!
One thing I will say - if you are going to get involved with hummingbirds you'd better have a lot of time on your hands because they can become addictive (not to mention feeder maintenance in hot weather because of the possibilities of mold, nectar fermentation, etc.). I actually bought a second one but I think I'll wait until next spring before using it.