I'm currently on O2, but my contract is up next month. I was looking to switch to a sim only plan to save cash. I saw GiffGaff do a pay as you go 'goodybag' for £10 per month which gives unlimited data, Unlimited texts and 250 mins. This would be perfect for me as I mainly text and use data. I just wondered what experiences people have had with them, I understand that they run on the O2 network, but will I get the same data speeds etc, I'm worried that O2 slow the data down for non-customers so to speak?