Yes ... it will sound quite a lot different! Both will have a bunch more overall volume and more bottom end. The Reaper, especially will sound a lot "bigger and beefier".
I'm curious what speaker you landed on for your spitfire clone. I have a spitfire clone coming my way and I am needing to select a speaker as well. I know that Matchless uses a G12H30. I have a 1x12 cab with a Veteran 30 in it, but I am curious about the Reaper too, and how that will differ from the Veteran 30.