I was hoping to hear from everyone about what type of weight system they use and why. Also, why do you not like to use other weight systems?
I have used weight belts, integrated weight BCDs, a weight harness (DUI Weight and Trim), cam band weight pockets, and weights tie-wrapped to my BCD or threaded onto the shoulder straps. I also consider a stainless steel backplate, and a steel tank to be a form of 'weight system'. My personal bottom line: I prefer diving a SS BP, with HP steel tanks, and a web weight belt. My experience:
Belts - I have used webbing weight belts, and rubber weight belts with a wire buckle. My overall preferred weight system ends up being a standard web belt. Pros: inexpensive, easy to use, fully functional, reasonably easy to get weights on and off. Cons: puts most of my weight on my waist, therefore can contribute to foot-down trim. In a drysuit, I have to cinch the belt down pretty tight to make sure it stays on / doesn't slip down, and that can affect the movement of air in the suit. For, wetsuit diving, it is very simple, utilitarian and my prefered approach. Rubber weight belts are nice, wire buckle works fine for me in OW, standard weights are a pain to change (you need to set the belt up with the weight you need and keep it assembled). While the theoretical advantages are great (stretches at the surface, contracts as your neoprene compresses u/w, I don't find it much better than simple web belts. Based on comments in this thread I will also try a Rob Allen belt, to see if I like the buckle, and will probably pick up some of the Mako weights to see if that makes using a rubber belt easier.
Integrated - my first BCD was a weight-integrated unit (Zeagle Ranger). While I liked the Ranger, and initially thought WI was great, I ultimately decided that I did not like having a back-inflate, weight-integrated unit, when diving with a bouyant tank (e.g. AL) and/or thick exposure suit/drysuit, requiring a substantial amount of weight. Pros: alowed me to not have to use a belt (which I liked at first), easy to use soft weights (put them in the Zeagle weight bags, then put the weight bags into the BCD pockets before a dive, and take them out after the dive. Cons: under the conditions I mentioned above (bouyant tank, thick exposure suit), with the weight positioned in pockets essentially in front of me, and my lift (in the wing bladder) positioned behind me, it tended to push me face down at the surface. Underwater, it was fine. The oveall downside is that the BCD itself was positively bouyant, and added to my weight requirements, so I stopped using it.
Weight harness - I used this approach when diving drysuit, with an AL tank, and a weight-integrated BCD. I needed so much weight in that configuration, that I added the weight harness because the pockets in the BCD (Zeagle Ranger) were aproaching volume capacity. It is my least favorite weight system, more trouble than it was worth, and frankly too bulky / cumbersome - in that configuration. Pros: added a place to put weight, besides the integrated pockets on my BCD. Cons: generally put the weight lower on my body than I prefer (although that was not altogether bad early in my drysuit diving), expensive, cumbersome.
Cam band pockets - definite asset with AL tanks, and I like using them to adjust trim, since they can be placed 'above' my waist (on the upper cam band), as required. I don't use / need them with steel tanks. Pros: fairly easy to use, can be used with soft weights or hard weights, helps trim. Cons - definitely not ditchable; some pockets (Halcyon) may be a little pricey.
Weights tie-wrapped to my BCD - I use this approach with a soft BCD, where I need more weight to compensate for the inherent buoyancy of the unit, and I don't want to put all of it on my waist. So, I tie-wrap two 1- or 2-lb weights as high as I can on the back of the BCD, or thread them onto the shoulder straps if possible (I can do that with a Transpac), taking 4 lbs off my waist. Pros: easy to use, helps trim. Cons - definitely not ditchable.
Don't know if this will help you, it is just my personal experience.