I installed 200sqft of slate tile and used these. It takes a LOT of for that that much tile and I was limited to how much tile I could put down during a day because I didn't have enough tops nor spacers.
The 1/8" spacers (or larger) are the only ones I'd recommend. The 1/16" spacers break too easy. In my case I used both because neither was large enough for the 3/8" gap between the natural slate tiles that I used required.