I've made the savoury base (the big one), but not the melting base yet (the current one). The curries I made with it were great, as good as I've made. I also made the balti base, which was nice as well, but I preferred the savoury base. Haven't made the current ones like the Saffron from this site yet as I haven't been making curry for a while. Last one I made from here was Stew's base, and I've also made Darth's... In fact, I forget all the ones I've tried now.
Regarding freezing, last time I was making curries, instead of making the base and freezing it in portions, I made all the curries right away and then froze those instead. It seemed like a good way to work, albeit rather labour intensive.
R.