It depends on what you want to use the machine for. If it's mostly woodworking with occasional light/Medium aluminum work then this design is more than capable. The only negative being at this size it needs two ball-screws on the Y-axis.

I've built this style of machine for many years and the high gantry sides are not an issue for the type of work described above. This gantry design is stronger than it looks so don't be put off by the high gantry sides. However, if you are wanting to Hogg aluminum away with aggressive cuts and higher feed rates then high sides and gantry sat directly on the rails is a better way to go.