Have you read the millions and millions of threads on the subject of BP/W vs standard BCs, and on the hogarthian vs deluxe harnesses? Go over to the BC forum and start reading, in a few months you'll be finished (if you read every day) and then if you still have any interest in diving you can make up your mind.
There's very little doubt that a backplate will work better for doubles. No matter what anyone on this or any other thread will say about it, most doubles divers use backplates, and there's a good reason for that.
The transpac is a well made thing, but it was designed from the beginning to be used carrying tanks on land for dives that required a long walk to the entry point. The function of gear on land has very little to do with how it works in the water where the weighting and balance is completely different. It was also designed to be versatile and as such it's probably not ideal for any one thing, definitely not doubles.
The comment about backplates feeling like a straightjacket is absolutely false, nobody else that I've ever seen using one or even read a post by about them says anything like that. In truth the simple hog harness provides a much better feeling of freedom than most other systems because there's far less clutter on the harness, the shoulder straps are typically looser than other types of harnesses, and the whole thing kind of disappears when you're in the water. At least that's the overwhelming majority experience of people that have used both the BP/W with hog harness and other BC/harness systems.
