dixie, just in case you don't know what DPCV do, it keeps an implement from dropping down even if it looses pressure. It has to have a certain amount of pressure to move it. (correct me if I'm wrong, please)...if you want a dpcv i have them on my my cylinder...
MtnViewRanch does not have that but his can "float" in and out when you need that function. His will also hold an implement in place but if your valves leak, that will also be seen in the implement dropping down.
Both have their place and use... You can do plenty of reading about both types by searching "DPCV"...