I had that response written in my mind as soon as I saw your nick under "Last Post," strippers be damned!
A weblog would be a good way to get your thoughts down in writing, without any formal restrictions. However, there are benefits to writing, or having the intention to write, a book. For the rest of your life, you can tell people that you're researching, like Emily Post in Cold Comfort Farm.
My brief posts take longer to write that my long ones, generally speaking. Back during the Gamesquad era GAF, it was important to me to figure out exactly how I felt about certain (especially political) things, and why. Unless the topic is a repeat, or a narrow factual matter, there tends to be a lot of introspection on my side.
It's also better from a practical standpoint. I rarely post except when I'm disagreeing with someone, and I don't want to get bogged down into one of those awful back-and-forth fisking with twenty quotes and individual retorts for each one. I try to say the core of what I think, and assume people will understand. If they don't, there is always the option of posting a clarification. You don't have that freedom with formal essays.
Interesting that your short posts take longer than your larger ones. Makes sense in a way, though. Yeah, introspection is always good -- always better to think before you speak, which is why if I haven't given an issue sufficient thought I'll usually refrain from offering an opinion. I don't want to put my name to something that isn't well-considered. One of the reasons why my longer posts just flow out of me is because I'm pretty much
always thinking about this or that. I don't really have to stop and consider my position because I've already given a great many things a ton of thought over the years. That's not to say that others (such as yourself) are not as reflective as I am -- I think it's a combination of the fact that my mind never really "stops" (and I wish it would many times), and that I have few obligations as compared to most other people (i.e., a career, family etc.); these conspire to produce ample time for rumination.