I think I tried Heed once or twice at full strength -- not too high in sodium but taste was awfully tame for the suggested dilution and it sent me high (half strength? may need to try that).
I usually take Ultima Replenisher since it's a full-spectrum electrolyte replenisher (Na, K, Zn, Mn, Cr, Mo, Cl, Ca, selenium, vanadium as well as vitamins B1, B2, B6, B12, folid acid, biotin, pantothenic acid, plus choline and inositol, sweetened with stevia)... so far the only full-spectrum replenisher I've found and not hugely high in sodium (37.5 mg per packet, 2 packets per bottle, 10 calories/ 3 g carb per packet.
In summer I find I need to pace about two sports bottles of fluid per hour riding,but I haven't calculated electrolytes perfectly (just, if I'm feeling faint when I stop, I didn't take enough of them -- and if I start getting a headache, I probably need a glucose-tab's worth of carbs regardless of what the meter says).
I'll look for the other stuff next time I'm in the cycle shop -- probably tomorrow if The Other Half gets his requested day off so I can pre-register for Sunday's Tour de Cure.