WordPress is, far and away, the best blog software (and particularly software ecosystem) out there. I wish there was a Railsy alternative a fifth as good, but there isn't.
I'm building yet another blogging platform (not quite) right now. It isn't going to be Wordpress, but it will be managed and won't cost you $200/mo. A carcycle, if you will.
To carry the analogy to its end: you seem to be only using the car to drive ten blocks to work. In other words, you only serve static content + comments. Which is why I'm curious what, specifically, compels you to stick with Wordpress even though there is an obvious cost (be it money or effort.)
I know you run a business, so for you the answer may be 'yes', but for most people running a blog: is this really a huge concern?
To borrow an upthread analogy, if I'm switching from a car to a bike, whether I'll be able to get a complete paintjob at 3am for $70 without talking to someone is not really something that's going to make the pros/cons list.
In OP's case, he's spending money on hosting a CPU-intensive blogging engine. In theory he could spend the same money on theming an efficient one.
If you want a huge plugin ecosystem and easy theming then yes, it is the best. You just better get caching right because it's going to hit your database 100+ times per page load once you install those themes and plugins.
So - what is closer to the best blog software? Better yet, what is the best blog software?
Radiant CMS http://radiantcms.org/ . I don't even know Ruby well and I find it easy hack on, add extensions, and take features away that would get in the way of the client using it.
(This is partly a genuine question and partly a rant caused by seeing my VPS go into swap death spiral when the googlebot came around, just because WP apparently couldn't serve more than about ten simultaneous requests. Intellectual curiosity says I'd like to know, but life really is too short to go back to having to deal with it fo rreal)
It always starts as a "Hey, I can just have this static page". Then, "...well I just need this simple feature, and I've been wanting to learn node.js anyways..."
The historical problem with "blogging" is that it was invented in an era where we didn't yet have Disqus, Flickr, Instagram, Facebook, Twitter, Feedburner, YouTube, Slideshare, Google Analytics, or even Digg, Reddit, or Hacker News. If you wanted any portion of the functionality of any of these things you had to build it into your "blog". And so hacker blogs were enormous code-heavy things that tended to get heavier with time.
But nowadays I'd argue that, to first order, any work you do to reinvent any of the functionality of any of these things is an expensive luxury. Others have concluded the same, which is why so many blogs have shed so many features and gone back to being: A bunch of static web pages full of writing. With maybe a sitemap and maybe an RSS feed, and maybe comments with Disqus, but maybe not.
But I'm always curious to know what I might be missing out on if I switch to Octopress, so please: A list? Sell me on Wordpress!