Those are basically the furthest places you can get for 25k, AFAIK. All North American destinations have the same miles cost, so LAX is good value. They could easily choose to make South Africa cost more, but for some reason they don't (even though redemption availability has been historically poor) so CPT is a great deal. GRU is not as far as CPT, but costs more .

I'd rank the best value miles destinations as CPT and TLV. The latter costs only 10k to upgrade from WTP to CW but since WTP usually isn't that cheap (for the distance) and it's a 777 anyway, full redemptions are sometimes an even better bet: a cool 60k for an F return. ^