giffgaff is fundamentally the same as any corporate entity and always has been. There is a veneer of "otherness" but that is all it actually is.
If I had to pick a difference then I'd say that you're the only mobile company who tries to pretend not to be a for profit company, instead attempting to masquerade as a cooperative of sorts. Marketing.
I don't think that's necessarily a bad thing, it is after all clearly working to a not insignificant degree which suggests long term viability in a market strewn with casualties meaning that people can rely on the company being around for some time which is important.
It does have drawbacks though, such as fostering a cult like mentality where you have your "support staff" making absurd claims which are detrimental to the public perception of the company, (see "payback" claims - another company just gave me "payback" which is £2049+ in value when compared like for like with giffgaff, purely for agreeing to stay for two years when I've zero intention of leaving anyway), and creating a perception that support is provided by a pack of rabid fiends cashing pennies, (something that I hear often and whilst it is true in many cases respects, it does a tremendous disservice to many of the individuals providing truly exceptional service to customers).
So double edged sword there.
Years ago giffgaff did feel like it was different, a lot different, but that was in the days when the network was being built and you had a very geeky userbase and public perception. That made it feel fresh and exciting.
As the network grew innovation naturally slowed and giffgaff changed from a trendsetter to just another company, part of that is financial, part of it is the rest of the market catching up, part of it is the changing demographics and company focus, (which whether real or otherwise feels much different these days).
On the putting members first thing, as someone who has always positioned themselves on the outside of that I'm able to take a somewhat objective view of that. That too seems to have changed and that's due to the staff and their attitude towards members and myself.
Years ago it wasn't a chore to hear from staff, it was pleasant, they were friendly, respectful and decent, clearly very good at the whole customer service stuff, these days I dread them getting in touch.
I walked into my other providers local store the other day to pick up a new phone and was greeted by the store manager, (someone I haven't seen in about a year), and when going through the process he was friendly, polite and welcoming. He even demonstrated that he remembered me, making jokes relevant to myself.
That's how you used to be. That's part of what builds relationships, that's what makes the customer feel valued and makes them want to stick around. And it's the same however I contact them or however they contact me. That's how once upon a time you had my loyalty and how they now do.
It is important now that you're essentially "just another provider" that you're honest, open, genuine and work on building the reputation of being a friendly, knowledgeable company who values their customers, (members if you insist), because these days that's how you will differentiate yourselves from the pack.
Failing that you need to find a new way to innovate in what is a very stagnant and homogeneous marketplace as you were once able to do with considerable ease, because that's the other way you could set yourself apart from the pack.