I was with BT who were fine but weren't perfect. Since it's become EE/BT it's been total rubbish. Most recently, I contacted them 2 weeks ago to tell them I was moving house and booked an engineer for the install. The engineer never turned up - they claim some bug meant my old address went in so they just cancelled the booking without contacting me - and now the next nearest install they can do is nearly 3 weeks away. So they've left me at my new house, unable to work from home because they totally failed in one of their most basic tasks.
No one who I spoke to seemed to have any sympathy for the situation they've left me and my partner in. I've gone to the communication ombudsman this morning and I hope EE get hammered. I'll be leaving them as soon as I can after I get some compensation.