I fail to see the difference between using ankle weights v heavy fins!
There are a few differences.
The ankle weights are one more thing to have to remember, and one more thing to have to put on.
Jets cost about $50 used. Ankle weights themselves often cost around $30.
Some style ankle weights are more snag prone than others.
Your ankle weights are a lot more likely to break or fall off than some Jets+Spring Straps.
On the other hand, you can always take off the ankle weights and use the same fins when you are diving a thinner wetsuit.
Ankle weights can be more of a quick fix solution to a trim problem, and you can experiment with them a lot easier than with other forms of weighting.
Next step might be heavier fins with spring straps, such as Scuba Pro Jets or OMS Slipstreams (Jets are heavier).
My slipstreams are almost neutral in saltwater, FYI
I guess my question is, with only 4 pounds of weight at my ankles a problem, with all of my other weight ditchable?
Ditchable weight requirements are a whole 'nother can of worms. If you need ankle weights, I would assume you are already wearing a fairly thick wetsuit. That would make me think you would have enough weight in another form to leave a substantial amount for ditching.
To me, ankle weights are ditchable. A steel BP, and HP130 are not. Weight strapped to your cam band is not. I normally don't have any ditchable weight on my rig. I am not overweighted to the point where I would have trouble swimming up from depth should my wing fail. If I'm on the surface, I am very confident in my ability to inflate my wing either by the power inflate or by orally inflating it. In the unlikely event of a total wing failure on the surface, I should be able to tread water long enough to get to the boat, or even inflate an SMB if I'm going to be around for a while...and in cases of dire emergency, my entire rig becomes ditchable weight.
Tom