I *detest* weight belts. They *never* stay where they should.
At this point in my diving, I *rarely* have ditchable weight. I'm negative even with zero weight even with a drysuit, so there can be nothing to ditch! However, before I learned how to *actually* dive a drysuit, I *did* have extra weight, and I used the same type of DUI harness that
@Marie13 is mentioning.
From a comfortably holding weight perspective, the thing is *great*. At one point I had 20 pounds in the thing, 10 on each side. Carrying it around was no problem at all, in or out of the water. The harness gave great stability and support, and yet it still had 'pull this in emergency' dumps. Very nice setup.
The biggest disadvantage is that, even if you only have a couple of pounds in it, the thing is bulky. It can interfere with your BC/BP waist strap, and the big pockets are still big even when it's empty. If you've only got to have a few pounds, I'm not sure that the comfort and convenience is worth the bulk -- especially because a 5-pound weight belt is less annoying than a bigger weight belt, too.
One other thing: if you forget to put this thing on, you are going to have to take *everything* else off to put it on. No slipping it on like a forgotten weight belt...
And one last thing: don't start making big weight-management decisions right now. Sure, if you have the money, buying the DUI harness isn't that expensive, and you can likely resell it later; however, ideally, you will be also improving your technique such that you will use less weight. In my case, I started out using 20 pounds of lead with my drysuit: I used to use 6 with my wetsuit, and no one seemed to think that this was that unusual. But then I started *really* working on my technique and my buoyancy. I was able to get it down to 10 pounds and I was pretty pleased -- in fact, I thought that I was done.
Nope: later after taking Fundies and making some other improvements, I was able to get down to zero extra weight (in steel doubles). What changed? Two things: first, I had to get to the point where I was *absolutely* *flat* in the water, and therefore my fins were not pushing me upward -- which most people do, and which causes most people to think they're "light" when in reality they're actually just finning themselves upward and using the extra weight to counteract that. And second, even then, because of having spent so much time overweighted in my diving career it took me at least 50+ dives to truly learn and understand what neutral felt like.
Anyway, enough off-topic pontificating. If you are trying to carry near-double-digit pounds of lead, the DUI harness is really nice, if a bit bulky.