I had been having some difficulties with MachBlog. Not that it's a bad piece of software, it was just giving me more headaches than it was helping to solve. So I went looking for a new piece of blog software. I originally had thought to go WordPress, but it's restriction to MySQL didn't work for me. I thought about going back to BlogCFC, but didn't really want to go back to that for a variety of reasons. I finally decided on MangoBlog, from our good friends over at ASFusion. I like the look and feel and I love the setup process. It works great and should be pretty simple to upgrade, if I follow the directions.
If you previously had a subscription, you should be OK. RSS should stay the same as well.