Well I've done it, changed blog engines again. Part of it is that like Scott Hanselman says - "own your content", but really part of it is that I just like playing with new things.
I did consider switching to Umbraco which we use at work. This would been a great move, but very very safe. I wouldn't have learned anything from it.
Instead I threw myself in the other direction, a flat file php based CMS called GRAV. I did shop around a bit first considering a few other options, along with the idea of a static site generator too, but Grav looked just fun enough and developed enough to lead the pack. And it has, I've been blown away with how clever and easy (mostly) its been. The hardest bit is probably wrestling with Fasthosts to get it online (and that was a fasthosts two accounts problem). Honestly the speed of getting this off the ground (for me who hasn't done php in too many years to mention) was staggering. Any blog up to a few hundred pages should really give it a fair shout.
I'm going to keep throwing plugins at this thing to see how capable i can make it
Learn about Grav at ... https://getgrav.org/.