I think this is well designed and produced, but there is one feature that would make it a 5 in my opinion. There needs to be a rubber or silicone base, dishwasher safe, that fits exactly on the bottom.
1-to keep it from rubbing the countertop, 2-to keep it in place while using, 3-to enable easy cleanup of any spilled coffee.
So I gave it an 80% approval as-is.