in a nut shell
the go is plastic coated, more durable, and heavier. will be good up untill the point where you want to learn to chop hop, planing gybes etc. you'll be able to learn to gybe and tack on them but gybes will be a bit awkward. basically it will be a bit limiting for you once you reach intermediate level
the excite is more of an experienced-beginner to advanced-intermediate board, is lighter, faster, more maneuverable
if you are already sailing back and forth, but not necessarily planing, the excite may suit you better as it will take you further. You'll just have to take more care of it, as with most non-beginner boards due to their lighter, more fragile construction

more prone to nose damage if you bang it with the mast or boom