Carefully stepping round the toys on the floor.
Paul,
The fact that you havnt changed the 'o' rings on your Divematics might be a good reason why it is so reliable. Perhaps some standard AP DSV users can step in here. When you change the 'o' ring, it does not like to maintain the curve of the barrel and consequently steps out and gets trapped between the barrel and the housing. Ergo, you cant close off the loop without fiddling. How deadly could that be, especially in a situation where your going off loop involuntarily. This settles down quickly with use, but might give you cause to pause. Just a throw away point to keep you safe.
A constructive but critical evaluation of each of the BOV's would be of use. The BOB does have some nice features but they are heavy out of the water and notoriously difficult to maintain without an engineering background and free access to some weird parts. The swivel is a nice idea but in hindsight, a bit of a novelty that could you could be without if supplied with a quality hose swivel. My opinion.
Remember, Rolls Royce engines didnt used to have a head gasket! I remember being shocked by how easy the Submatix DSV was to operate the first time i tried it when I was invited to the UK launch. No 'o' rings, but not built as well as I would like.
Experience of a number of BOV's in use and ones under NDA at the moment I re-illiterate my previous statement that they have no advantage over each other. It is the way they are implemented that makes them succesful.
Brent.