Speedbrakes for a Bonanza: Opinions?

With my Bonanza about to roll out of maintenance with its new
(overhauled) engine, I have been considering ways to preserve that
investment.

Recently, I came across an article discussing speedbrakes and was
wondering if anyone here has experience with speedbrakes in a small
aircraft.

I see the main advantage being the ability to slow and/or descend
without having to significantly drop power, which keeps the engine warm.
If true, this would be an excellent way to maintain engine health.

Looking for any comments, either pro or con, about this modification.
Thanks.

--
Peter