Hello Allen & All,
I would like to add to Allen's post by saying many years ago I observed *bee
space* was not observed by the bees in the brood area.  In other words the
brood comb could by spaced wider (when using drawn comb) without the bees
making changes to the comb like they typically do when nine frames are used
in a honey super.  Because bees crawl over other bees when congested I
believe using nine frames helps with congestion at times.  With bees
entering the entrance and heading up to the supers the extra spacing of
another bee wide between all frames can help greatly with congestion. I have
had beekeepers say the above is not so but do the math.
I have pondered the question of simply removing a outside frame at the start
of the honey flow and putting back after the honey flow for those using ten
frames.
The biggest draw back I see with using nine frames is the practice of adding
foundation into the brood nest to prevent swarming. Often many of these
frames are drawn incorrectly because of the nine frame spacing if the bees
are bringing in nectar at the time.  The problem has got worse with the use
of plastic  foundation. Bess not wanting to use the plastic simply start
their own comb right between the plastic foundation and the drawn comb.
Quite a waste of the bees time and resources. At times foundation is drawn
in deeps with a inside feeder in place. The frame next to the feeder is
always a problem to get drawn correctly when using nine frames and ten will
not fit.
I still use mostly nine frames and have came up with ways to deal with the
above small problems. Using ten frames in late spring when checking brood
nests on strong hives slows down the process in my opinion. You really need
to start on the outside and remove a frame first to prevent smashing bees
(maybe the queen).  With nine *many times* a quick check of the brood can be
done by simply pulling up the center comb enough to check the brood pattern.
Time is the most precious asset you have got at the busy time of the year.
Typically hobby beekeepers use ten and sideline/ commercial beekeepers use
nine.
Sincerely,
Bob Harrison
Odessa, Missouri
Ps. Glen & Lloyd Stanley (Iowa) are strong advocates for using ten frames.
They are retired now but still provoke lively debates in bee meetings when
the *nine verses ten* discussion comes up. They ran thousands of hives
always using ten frames and I have learned countless beekeeping tips from
their talks and articles.