The iozone results seem a bit consistent and all values seem to be noisy and
not say much. I don't know why really, maybe the test is simply not relevant,
the tests don't seem to be significantly affected by any of the patches, so
let's focus on the dd and find tests.

Maybe use a more selective testing mode instead of -az.
Also maybe you want to clear the cache between the sequential and random tests:
#sync�
#echo 3 > /proc/sys/vm/drop_caches�
#sync�
It helps to obtain a more robust results.

What immediately jumps out at you is that linear read/writes perform just as
nicely or actually better with MQ than with the old block layer.

How come 22.7MB/s before vs. 22.1MB/s after is better?  or did I misunderstand the output?
Also as dd is probably using the buffer cache, unlike the iozone test  in which you properly used -I
for direct mode to isolate the blk-mq effect - does it really say much?