Which is the best roaming partner for London, UK?

bitracer

I've been using 3 UK today with lousy results. Very unreliable internet connection and abysmal speeds in 4G. Often dropping to 3G in central London.

Gaeilgeoir

bitracer These are the available roming partners in the UK,

And although I'm by no means a Vodafone fan, I had always good experiences with it being in the UK. T-mobile, O2 or Orange I never checked. No so good experience with Three I had in Ireland, similar to yours. Here also I switched to Vodafone.

bitracer

I'll experiment a bit tomorrow.

bitracer

I've been using the various providers over the last few days. The Vodafone works the best, followed by EE. Both 3 UK and O2 have issues.