The Freedom plate is a good option but not always available...or at lest not in the past, that may have changed and it's not something I could get locally - I like to get my hands on things before I buy.
I have several vintage options but I wanted something that could pull double duty as a standard BC and at the same time be a good platform for a DH reg as well- mainly so I did not have to travel with 2 BCs. This week I have been experimenting with a Zeagle Express Tech, basically a soft nylon BP/wing. It has several advantages that made it a choice for me. Besides being light (for travel) and very adjustable it has 2 tank bands, something I prefer. There is no need for a STA so the tank and reg stay close to the body, a requirment for a DH reg. A huge plus for me is the easy with which the bladder can be removed or replaced. I typically do not use the bladder unless required to by a dive op or dive conditions warrent. Being able to remove and replace it quicky with no tools (unless 2 coins count as tools) is a big plus for me. So far it's working out well. At $250ish it's fairly inexpensive as BC's go.
I am diving it all this week with a Phoenix, working out the bugs. After some messing around I have about got it. A crotch strap is pretty much mandatory otherwise it rides up too much and you have to add some weight belt keepers to stop the shoulder harness from "migrating"- it tends to "self adjust" and make the tank ride up. This (strap migration- riding up is a problem with any kind of BC) would not likely be a problem on a standard BP, the web routing on the ET is a little different. When diving it with a single hose the strap migration would not be an issue and at the same time, keeping the adjustment set for the DH is not really a problem with a single hose, you can leave the straps set and just move the tank up some.
I have even cooked up a simple and cheap weight intergration (non ditchable) modification for it that has worked great, no need for a weight belt. I dive with so little weight in warm water (4 lbs in salt) that the weights being non-ditchable is not really an issue. I can't speak for any other BP availible but so far the ET is working out well for what I wanted it for- works well with both single and double hose reg, light weight, bladder is removable and fairly inexpensive. I will likey convert the crotch strap to some form of saddle harness but otherwise the BC is about what I want/need.
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