We use CHIKKA as well. The problem with CHIKKA is it is more costly for anyone in the Philippines to reply to messages.
One advantage of Smart Plug N' Talk over Chikka is it's ability to send load to mobile phones in the Philippines. My wife sometimes sends load to her sisters (when they don't have load to reply to her...) and where the minimum you can send with Chikka is 30 pesos (costing $1), she now sends 10 pesos (maybe costing £0.15).