Is it better to reduce MP and leave RPM at
2200?

In my Mooney I like VFR decents at whatever speed I had been cruising. It's
my
habit in cruise to keep the RPM low, almost always going a little
'oversquare'
(MP in inches a bit higher than RPM in hundreds). I don't like speeding up
in
the decent, and consider the altitude energy in the bank, I spend it on
haaving
the MP lower.

But your giving up all the speed you should have gotten back from the
climb. You fly slower in the climb but get it back when you start
down. Pulling power back just gives it all up

I admit to not running the numbers on that. I figured I chose an airspeed that
made sense, save a little fuel on the decent, and even if I come down from
11500 at 500 fpm it's what -- 21 minutes to pattern altitude. At 150 kts +
wind, that means I start down about 50 miles out. If I come down at an average
of say 165 ktsI'd be starting down maybe 8 miles sooner. Maybe it's as much
this as anything -- I mostly do XC under IFR, and like to keep whatever is the
filed airspeed.