It really depends upon what's under the durock. If your subfloor is strong and stable, 1/4 inch would work fine.

You might address the transition heights with reducers that match your flooring.

If all else is splendid, then the 1/4" lip will not be a big deal in the long run. A 1/4" lip is usually not a tripping hazard for most people. And, as djlandkpl says, reducers can be installed later, if for some reason the small 1/4" lip is a walking problem for you.

thanks to both replies -

the 1/4" rise in the tile is frustrating as heck - new build, things should be perfect :) Under the durock is brand new 3/4" osb with a silent floor system. The rise is in 4 different places and just ticks me off.

I just wonder if they used the 1/2" durock b/c they used it for showers and for some reason it's easier not to mess with 2 different products. I don't really buy the stability story.

And there isn't much choice but to live with it. :(

Sue,

I hear 'ya, but you know what?...very little in life is ever perfect. If everything is near perfect, that is more than what most folks get who have new builds done.

I worked a high profile job for a famous tennis player and his Broadway actress wife...and you would think that their contracted work would have been perfect, but it wasn't even near perfect in my estimation...except for my work, of course! ;-)

Sorry your job isn't perfect. I do feel your frustration, as I am somewhat of a perfectionist also. But, I have learned over the years that small annoyances and disappointments, such as this, soon diminish with time and become inconsequential.

Good luck with your new house.