I have plenty of alignment tools, going all the way back to the original Dennesen, which was excellent. Of them all, my favorite is the original Wallytractor. These were made specific to each arm, unlike their current universal model. What's great about the Wallytractor and others such as the Mint is the mirrored gauge. That allows you to align the cantilever itself and once you've done that, it's difficult to accept any other approach to alignment.
But - that little cardboard gauge that SME ships with its arms such as the SME V? Genius! It can get alignment very, very close. But like all unmirrored gauges, it makes assumptions about your cartridge.