Sorry, I've had the flu and am just now crawing out of my coffin.

Carl at Sartek has built some slick digital secondaries that allow you to see all three sensors at the same time. I've done a couple of dives with it and I think it gives you a better idea of what's going on with the sensors.

The Peter philosophy on the analog secondary is that it will work even if the battery cap floods, which is a valid point. The digital one will too, but of course it's got a battery in it. I haven't had any trouble with my stock analog one, but they are supposed to be delicate.

As for weight, the Prism is a pretty light unit, which is a good thing overall. It does have a big loop volume. Some people have tried to solve weighting issues by using big steel backplates but as I hate backmount anyway, I didn't want to do that. I trained on a rig set up with one and struggled to trim it out, as too much of the weight was down low.

When I got my rig, I took it straight down to cave country and spent some time getting it sorted out, and it really helped me to improve the trim. I'm using a homemade composite backplate that I inherited from my friend which works really well. It's got a lead bar across the top that we sand casted that probably weighs 7 pounds, and in fresh water, I put a fiver in each counterlung. In salt water, it depends on what kind of suit I'm wearing but I add some weight into the cumberbund pockets.