After using sipdiscount.com for a while, I recently found out they significantly raised their prices. Their list of free to call countries is now very short and they are certainly not that cheap anymore. So I started looking for an alternative.
I ended up with voipcheap.com that appears to come from the same mother company (Betamax), but with better prices (for now). They have a nice fee days policy, meaning you get 90 free days when you pay your credit. When the 90 days are over you will not lose the credit, but you will pay the ‘normal’ rate for calling the free countries in their list. The list at voipcheap.com is longer than the one at sipdiscount.com.
I found switching accounts on my SPA-3000 very easy. I just created an extra gateway account and edited the dial plan. This allows me to easily switch back to sipdiscount.com when they get their act together.
For price comparison I found this site very handy. I will certainly use it again when prices start changing at voipcheap.com