It depends on what one's personal requirements are, hussain1988. For some on this site, it may be the case that Vectone's £15 UK and Europe Popular tariff may represent better value as it includes "unlimited" calls to landlines in Europe and the US and Canada:
http://www.vectonemobile.co.uk/paymonthly/Pay_monthly.aspxAs with GT Mobile's data, anything over 5GB gets reduced from 3G to 2G.
However, I should stress that this plan does not seem to offer the benefit of 4G data.
I think that you are quite right to draw attention to Vectonemobile's alternative Graham.
But of course there may be problems with it, due to it's running on the EE network.
But I am unsure whether you are right or not in your last sentence.
When I go to
this page I see clearly the following statement:-
The UK's NEW mobile service offering unbeatable value bundles & 4G data, all on a high quality network
Further down it says:-
4G included at no extra cost
So here is appears that the data IS 4G - up to 5GB as you say - but gets reduced once that figure is exceeded.
However the website is both confusing, and contradictory, because in the Terms and Conditions section is says:
Unlimited data usage is subject only to a variation of speed from 3G to 2G for usage beyond 5GB per month per SIM.
It may be this worrying confusion that lies behind your assertion that the data is 3G only, dropping to 2G once 5GB is reached?
If GT mobile can't be bothered to check their wording, and to present consistent information, perhaps that alone is sufficient to be wary of them.
It certainly makes hussain1988's championing of a service he hasn't yet tried look faintly ridiculous.