I made yam and sweet potato chips recently - both at the same time so I could compare the difference in taste (yams are more orange - sweet potatoes are off-white). The dried yams had a better flavor in general... the sweet potatoes just tasted very starchy, but had little flavor. Both were good with guacamole and decent with salsa.

I sliced them thinly on my mandolin. They shrunk quite a bit when dried, so the bigger the yams are around, the better. They also got quite wrinkly, as you can see in the photo. Andy liked the yam chips especially, enough to eat them on their own, without a dip!