I have used it myself over the past few months and would say in use it is pretty much like the amber cored but with a bit more power for the same diameter.
Available in five sizes.
1.8mm Blue 8-10
2.1mm White 10-12
2.3mm Green 12-14
2.5mm Black 14-16
2.7mm Purple 16-18
I now take payment by card on the phone call 07743 416559