I went from BT to EE last year in theory the same netwrk, when it was switched no engineer came to the house etc - i was very aware EE broadband has a terrible reputation, I took a risk as it was the same speed as BT, but with agood saving.
To start with it was actually a bit quicker, I went off and did some research first job I switched my BT socket to enable it to use the 'test' socket, no real difference to be honest, I then decided to buy my own router so I bought a good router and I kid you not i virtually doubled the speed...yep almost doubled. never had any reason to call EE and fingers crossed its been spot on I use home network plugs for my tv and ip camera - being in the back ass of nowhere im fairly happy with my speed now.