This week, I finished my Thunderfire Cannon and Techmarine Gunner for my White Scars Space Marine army.
The Thunderfire Cannon is a strong option for the Space Marine army in 8th edition. If you want to know more, you can check out my review for Frontline Gaming. It talks about some of the useful tactics for using it in your games.
The Tremor Shells stratagem is pretty effective, allowing you to slow down an enemy unit for a single command point.
I've been using the Cannon in my last few battles that I need to write up, so you can check out its progress when they go up.