Which phone network is better, O2 or Orange?

[Gemma]

Hi,
I currently have an iPhone 5 and I am currently on a 30-day rolling contract with Orange in which I spend about £25 a month paying for Unlimited texts, 300 minutes and 500mb of data.

Now, since Orange/T-Mobile have been bought out by EE, my service with Orange has dropped dramatically, As in, my messages won't always send and I find myself having to turn my phone on and off for them to eventually send and my internet won't work at all even when connected to 3G - nothing with load, such as my email, Facebook, Twitter, etc...

So, I was looking into O2 and how they have a second-wheel company called GiffGaff and their "Goodybags" are so cheap for what they offer. I was just wondering how reliable O2 and even more, GiffGaff are as a whole? Would I expect service problems like I have been with Orange? The only reason why I want to stay with Orange is for Orange Wednesday's, but I'd rather pay less for my tariff and have it be reliable on me.

So, yeah. Sorry for the over-extensive story. Which one is better?

Thanks!