I use Castle machines for making pockets. I set the depth so an 1-1/2" face frame screw penetrates 11/16" to the piece being attached. Castle really does have the best angle, and the pilot hole is beneficial over the step bit the kreg I assume still uses. I have one setup in the face frame area for doing frames using their solid carbide serrated tool. We do not run engineered material on that one. The other one is near the benches and I use a 2 flute tool, as we'll use that in any material necessary.
I like the Deerborn fine thread screws for most materials, but keep some of the kreg brand course screws on hand for softer material like alder.
Assembly, I think the castle brand tables are too squishy. I've got a Unique brand 5x12 assembly table that I'm a fan of. Good angle, and it's super stiff. The Ritter table is good too, but it's angle is much flatter, and stuff up high is a bit of a reach. I'm 6'2" and have a decent wingspan.
I wouldn't bother with a used Castle. New ones aren't that much more, and the old ones you will struggle to find parts for the discontinued routers they have.