I like Tracphone
Only had one complant, and that is that it is impossible to recharge by CC if outside USA.
I have two in regular use, and provided you keep credit topped up no problem, if you run out of credit, then just on arrival, buy a card and top the phone there and then.
Mine (LG) have GSM type SIM cards, no idea if they are transportable.
We changed from dedicated GSM mobiles with USA numbers, to Tracphones as they give us better quality of service.
Any more problems please PM...
Glf