O'Malley,
I have a DSS single tank rig, so I figured I would respond, although I have limited experiences with it. FYI, when I was considering my purchase, I contacted Tobin at DSS through email at
info@deepseasupply.com and their website at
www.deepseasupply.com. He was very helpful in answering any specific questions I had about the rig and how it would work with my current gear, and was a very nice person to deal with in general.
I am a novice diver, only 14 dives since I was certified, so keep my lack of experience in mind. 6 of these dives have been with my DSS single tank rig, 4 in warm water 2 in cold water. My firt 2 warm water dives were in Texas with no exposure protection, swim trunks only. I found that I did not need any weight in addition to the backplate to keep proper bouyancy throughout the dives. I prefer to use ditchable weight so I bought a 3mm wetsuit before my next 2 warm water dives in Turks & Caicos. The single tank rig backplate is approx 6lbs neg, and I used the dive boats weights and weightbelt for ditchable weight. I used 2-5 lb weights with my 3mm wetsuit, with the weights positioned on the front of each hip. This configuration worked perfectly for keeping good stable trim throughout both dives.
Since you are from the Chicago area you are probably more interested in the cold water dive experiences. I dove once at Cape Elizabeth,Maine and once at Blue Springs Quarry near Shelbyville, IN. Both of these dives I used full 7mm farmer John, hood, gloves, boots. Both dives I had the 8 lb weight plates attached to the SS backplate to reduce ditchable weight. In Maine I was using a rental aluminum 80 tank with 34lb total weight in salt water, the rig is 14 and I used a 10 on the front of each hip. This was too much weight, but it was my first salt water dive in full 7mm and didnt want to be underweighted. In Indiana fresh water I used my Steel Worthinton 100, with 22lb total weght, the rig is 14 and I used a 4 on the front of each hip.
The weight plates are wonderful for getting weight off your weight belt, basically you are taking 8 lbs off your belt which makes it easier to get on and off. But there is a caveat. I chock this up to my lack experience and limited use of the equipment, I am still learning. In my limited experience the position of the weight on your weight belt will dramatically affect your attitude and trim in the water. In maine I was using a pouch style weight belt with the weight distributed around my sides. The first thing I noticed was it was difficut to get face down horizontal. The natural position of my rig put me with my face to the sky and my body at about a 30 degree down angle with my feet higher in the water than my head. It was not difficult to correct my position but it wasnt a comfortable feeling. To correct this I found that I just needed all the weight on my belt in front of my hips. Once I found out where to properly position the ditchable weight everything became easy, and I had a wonderful dive and saw hundreds of lobster and crab.
I had the same issue a few weeks ago in the quary in Indiana. The 14 lbs on your back plus the weight of the tank has a tendency to roll you over facing up, this is with no air in the wing. This was my first dive with the rig, with weight plates, in fresh water, with full 7mm exposure protection. So this was my dive where I get to figure out all the proper weighting for bouyancy and trim. Once again when I figured out how much weight I needed and were to position it properly, everything became easy. I was horizontal, bouyancy was good, and trim was good, and I could enjoy the dive without worrying about the weight anymore.
I also purchases a DUI weight harness. The instructor/guide I was with in Maine had one of these. I thought it looked neat so I bought one to try it out. It is basically a harness that you put on before you don your BP/W. It has pouches on the front of each hip with a top entry velcro closure. You just open the pouch and drop your soft or hard weight in the pouch. It has yellow quick release handles that ditch the weight out the bottom of the pouch in an emergency. In my limited experience there are both pros and cons to this device. It is easy to put on and adjust, its nice to just slide the weights in the pocket before you get in the water. You can take additional weights with you if your wife is cronically underweighted

. And you can use the pockets to hold other stuff until you have to dump your weights, theoretically you won't have to. The only drawback is the additional adjustment straps floating around, 2 suspender type adjutments and one belt adjustment. If you use a Hogarthian harness this will be less confusing for you, I have the pro-fit harness which makes it an issue for me. The only reason I bought the harness was due to the amount of weight I had to carry in cold salt water. I doubt I will use it again in fresh water.
In summary
The DSS single tank rig is very nice and I am very hapy with it. The weight plates are great for getting some of the weight off your belt, just be aware that you will have to play with the amount of weight on your belt and how you position it for proper trim especially in fresh water where you will have less weight on your belt. It seems that it eas easier to achieve a good balance of weight distributing it both on your back and belt, rather than having it all on a belt. You have a ton more diving experience than I do, but hopefully something I have said here will help you a little. I will say that what little diving experience I have, has become much more enjoyable with my own DSS rig than it was using he different rental BC's. Jacket style BC's annoyed me and I could never get them adjuted just right. With the BP/W once its adjusted properly, it feels like its not even there, and I have more freedom of movement in the front of my body.
Chris Henry