The truth of the situation is significantly different to this bizarre "survey". The Mobile Network Operators (MNOs) make extensive use of user and call classification to determine how likely you are to get service. The more you pay each month, the higher up the priority list you are. The MNOs claim that they do not do this, but it's very interesting to compare the quality (and reliability) of service for someone on an old "Orange" account against a much higher-priced 4G "EE" user.
It's an easy test to do - get two identical telephones (we most recently used two Samsung Galaxy S3s for this experiment), one on 3G "Orange" at £17 per month and the other on 4G "EE" at £48 per month. The "Orange" phone struggled to obtain even voice and text connections in most areas (we tested in both cities and rural areas). We swapped the SIMs between phones to eliminate the possibility of a defective handset. The "EE" phone had (mostly) flawless service....
When EE were questioned about this, they persisted - right up to board level - in claiming that they did not do this. However, the evidence is damning. This same experiment has been widely carried out with other pairs of handsets and on other accounts. In all cases the quality of service is invariably proportional to monthly charge. This is (of course) contrary to the terms of their licence, but getting OFCOM to actually do any work is impossible, so they're getting away with this.
A final proof was to do a little hacking of the SIM and of the phone firmware to (effectively) fool the networks by spoofing the mobile equivalent of the "user agent" - it's possible to get truly flawless service with a 3G-only phone on EE, but only by making what are probably illegal changes to the way the handset operates.....
EE know exactly who I am, and I'd welcome the time in court to defend my "libel", but they won't do it, so my friends and I will continue to use hacked handsets and get premium serice at a budget price.
Interestingly, O2 and Vodafone have similar user classification (if you're on "Tesco Mobile", you're SOL) but the differences are a bit less striking.....