Yup. Wordpress should be bottom of your list.
Great to use yourself as a CMS - rubbish to comment on.
The high PR sites are all anti-spam
The low PR sites are..well low PR.
Here's an idea (i ripped off - sorry to original poster wherever and whoever it was)
Get firefox and Imacros (all free) use a forum footprint (PhP or such like) and get blasting.
Once you have worked out a quick join forum macro - and created a spam email address for all the confirmations to go to - -you can absolutely rule.
Likewise Scrapebox can look for all sorts of footprints. Almost any.
Scrapebox and imacro (and maybe a bit of VB or Java or whatever) and you can cobble up something that will rocket you.
I don't mean a major tool - but a unique tool - one with a footprint no-one else uses.
Seriously - take the time to learn a little programming language (VB is dead easy, and the compiler etc are all free) put it together with a spinner, or a social networking tool, or scrapebox or whatever, and dominate in your own way.
Forget WP for comments. Get a list of a few hundred none WP PR5 sites you can post on, and scrapebox will suddenly be a massive addition to your linking system
Akismet? Kiss my ass more like. I use it on all by blogs, and it's close on watertight against crappy spam comments.
Be inventive, have fun
Scritty