I've read (all?) the questions and answers regarding slow draining vessel sinks but I'm still hoping for some help.

Just totally gutted our master bathroom -- down to the studs. Rebuilt everything and purchased a vessel sink (and custom vanity) and the sink drains slowly. Changed the piping from the tail to the wall and it still drains slowly. Installed an AVV (?) between the wall and the trap and it still drains slowly. Changed the piping from 1 1/4" to 1 1/2" between the tail and the wall and it still drains slowly. Changed the faucet fixture and the sink still drains slowly. Snaked the pipe into the wall -- no clogs. No problem with the toilet or shower. The only thing we haven't done is changed the drain fixture -- it's a pop-up; but even when we remove the mushroom cap, the sink still drains slowly.

Apparently vessel sinks have a big problem draining. Has anyone come up with a new / better solution? My husband wants to break out the wall and increase the size of the pipes. I want to sell the house.

Please help!