I'm looking at the same DGX BPW, and am a little confused about weight options. The small pouches look nice but are they ditchable? I was diving with someone this weekend that was diving doubles and seemed really experienced and he said all his weights are on the back of his plate (near the tank) and non-ditchable. Seemed dangerous to me but what do I know.
They are ditchable if placed within reach, you just open the velcro and pull the lead out (or let it fall out). If mine are placed on the high camband, I can't reach it, but I can on the low camband, or on the waist strap.
That being said, many divers don't dive with easily ditchable weight, and consider ditchable weight to be hazardous. The thinking here is that ditching weight at depth can cause an uncontrollable ascent, which is a very dangerous situation, especially if you are diving under a hard ceiling. And sometimes the weight will end up being ditched on accident, if the quick disconnect is not plugged in all the way, gets snagged, or something like that. In the event that you would want to intentionally ditch weight, most folks would agree that it should only be done once you reach the surface, and at the surface you could ditch your entire rig if the non-ditchable weight is a problem.
For me, I'm comfortable diving with ditchable weight, or without it. In cold water I dive with ditchable weight in the form of a weight belt. This is very useful in a thick wetsuit, because a total BCD failure might make it impossible for me to swim up off the ground. It's not so important with a drysuit, but I prefer the weight on my hips, so dive dry with ditchable lead on a belt too. I always don the belt under my crotch strap, so that it cannot be ditched accidentally, but could be ditched by undoing both the belt and the crotch strap. In warm water, I typically dive with only non-ditchable weight, and I don't worry about it, since the total buoyancy change throughout the dive is small enough that I could easily swim up, even with a complete BCD failure and full tank of gas.
If you're not sold on this idea, that's fine, but many divers are. If you search for "balanced rig" on here, you'll find many threads discussing the pros and cons. At the end of the day, both methods are dived a zillion times per year without incident, so it will come down to the type of diving you do, and your preferences.