The 234er is perfectly adequate for a monopod. Important to me was the portrait position. The possibility of a tendency to change one gets the monopod free. In addition, so weight is reduced.
The 234RC is a very simple construction tripod head. However, it is surprisingly stable. Fixation is achieved by a pleasantly large clamping screw. The quick release plate can be solved very comfortable with a sturdy handle. Funnily enough, has the quick coupler over a small safety lever. Thus unintentional opening is prevented. Very good idea. The Alugußkopf is processed very valuable. The tripod mount can be adjusted by means of the recessed threaded bushing to other thread diameter.
The price of the tripod head, I find a really original accessory under.
My conclusion: The 234RC is the perfect complement to my 685B. It is stable, well finished. Do what he is and is affordable. 5 stars for the Manfrotto.