Here's where two sheets meet and there was a little too much space left in between (least of my concerns):
Some areas of ours look like this, instead:
I called our contractor & he's coming to look at them on Monday, but so far, he seems to agree (based on the pictures) that these need to be ripped up and done again. The problem is that we don't have any extra tile-- these were kind of expensive and we only ordered what we needed. Additionally, they were special order (typically taking 5-10 business days to get here) but we paid $150 extra to have them sent two day air to get them here when the contractors said they needed them.