[Q] zpool mirror; read from preferred vdev(s)

Hallo, 

Using a zpool mirror; is there a way to set something like
a primary storage / preferred vdevs / read-first devices like it was in
disksuite using "metaparam -r [roundrobin | geometric | first]" or the
"vxvol rdpol [prefer | round | select | siteread]" to define a preferred
plex in VxVM? Will ZFS always use round-robin? 

In our example we want
to use a brand-new fast storage with hot-data tiering (ssd-caching)
mirrored/combined to an older/slower one... with round-robin we could
assume that every second read will be slower? 

Will the write
acknowledgement be commited after both writes so we will have no
advantage from the faster storage? 

Thanks in advance 

 - pressy