I'm in the same boat as Marie having used IO since the early 90s. I've tried others, and haven't noticed any improvement in any organisms, so I always go back, plus as Marie said it's still cheaper to buffer the IO than buy premium salt. The only salt that calls my name these days is D-D H2Ocean simply because it is natural seasalt. That is my only draw to it. I am considered trying it out, but I have 1 1/2 buckets of IO to use up right now.
I just moved to this area, and around here D-D is $85 and IO is $65, so the price is closer than BC where D-D $80 and IO is $40-45. Both IO and D-D make similar amounts of mixed product seawater. I know I definitely have a hard time paying $65 for IO!!
So I guess that's also a draw to D-D.
