As a user of the Vodafone broadband service I have to say it is rock solid - no outage so never had to call their support number. A solid 60Mb download and 19Mb upload and I get this at any time of the day or night with no download limits. I have just signed up to a new contract for 18 months of the Fibre 76 product for £30 a month including line rental which I consider quite the bargain.
However their router is utterly crap with poor wifi coverage - I have Ethernet cables running off it to the rest of the house and a range extender that has much better wifi coverage than the router. Factor investment into a better router/range extender as part of any decision to move to Vodafone.