Best production gauge I've used is the Anderson. The filing plate is angled down at about 15° and guarantees a good crisp edge on your rakers. The shoes are slotted, which allows them to be slid closer together for smaller toothed saws. They will be pricey on Ebay though (~50.00).
Anderson on bottom, two smaller gauges perfectly fine for one man saws on top.
Anderson at work resting on two closest teeth:
Anderson on bottom, two smaller gauges perfectly fine for one man saws on top.
Anderson at work resting on two closest teeth: