I'll start a new thread on this as I'm getting a bit off topic, but wanted to add some more to what I've already written above. In addition to Lebara, I tested Lyca & ID-Mobile SIMs in my 4G router. The speed differences were quite noticeable with Lyca at 28M, Three at 5m and the odd Lebara behaviour where it starts high and rapidly sinks to 1m.