I have been debating that myself. Most of my posts are long (super long for some people's taste). >1000 words.  In fact that is my heavily stripped down version from the first draft :). If no one likes long posts, I will have to tone it down...

I'd say if you have that much to say on a topic, go ahead and write the 1,000 words, but instead of hitting publish, go back and see how you can break it out into a series. With that much to discuss in one article, I'd guess it would make a great series, which would keep people coming back to your site, rather than bailing out of reading an article because they're not done with it by the end of lunch break

I try to get my point across as succinctly as possible and check out two of my posts and averaged 800 words. I use bold headings too to break up my points.

too much content is like not enough ;-)

My posts are usually around 500 words.

As for writing, most of my posts hover around 500-600 words. I just naturally tend to be somewhere in the middle.

That said, as others have mentioned, there are pros and cons to both approaches.  Shorter posts are easier to read, easier to digest, and easier to respond to.  If they are well-written and provide useful information, they can be an effective way to get a point across and share the information you need to share in short, digestible nugget.  OTOH, you have only so much time to keep your audience's attention, which means less time for you to impress them enough to turn them from a casual browser into a serious fan.  It also makes it harder to share more than one or two links per article without looking like a spam site.

Longer posts have a much higher chance to pull in readers (and all other things being equal, probably a better shoot at doing well in Google rankings, although I am a novice at such things and can't say for certain).  There's also more meat for your readers to chew (metaphorically speaking), and thus, more for them to consider and comment on.  OTOH, there's a larger risk that your readers will be distracted or otherwise not read through the entire post if you opt for longer posts, particularly in our low attention span culture.  (I'm as bad as anyone; I have about a half dozen windows open as I type this response, and have flitted back and forth between them as I think of what to write.

While there's probably no perfect length, it sounds that something in the middle somewhere (perhaps around 500 words, where most of the answers given seem to converge) would be best.  Not too short that your audience thinks you have nothing to say, but not too long that nobody can make it through more than one of your posts before they simply can't read any more.  Although, you need to write how much you enjoy; slicing your posts down or stretching them to meet an artificial word count doesn't help anyone. 

My posts that get social media success are usually shorter, but my posts with the most interactivity are longer.

If you only use one length, your readers will probably get board. Mix it up and give topics an appropriate length.