just to close the book on this one...

tile floor all done, looks great.
can't say I did a perfect job, but it still looks like a pro put it in.
when they say watch the water cleaning off excess grout they're not kidding.

out of curiosity...
one tile seems not to of adhered as well to the thinset as all of the
others. You can hear the hollow sound when you tap on it. As odd as this
may sound I remember laying that tile and the bed of thinset was as good as
any of the others. What causes that kind of thing? I'm thinking it may
have been a locally uneven floor but there were a couple of spots like that
and the thinset floated the tiles on them fine except for this one.

anyway, thanks again for all the advice folks provided regarding this.

ml