I’m nearly done gathering and printing all my parts for a shapeoko 2 following the “big” plans for a 4x4. I really haven’t seen any comments if the larger sizes are more obnoxious or annoying (or worth it) and wanted to double check before I commit this January.
Also one thing I have not ordered is the router or spindle. I’m seeing a lot of positive feedback for dewalt spindles, but not sure which model.
I agree with Frank, just be ready to double up on the X and Y axis. The added stiffness is needed due to the added leverage from the size increase. The min speed on the DeWalt dw611 is 16200+/- RPM meaning you need to keep the feed speed up to avoid heating up your cutters, but this also means added stress on the machine.
One advantage of going with a common spindle is more attachments and mounts and things available for it. I don’t think you can go wrong with either of those Dewalt spindles. Inventables sells mounts for both of them. Lots of community mounts too.