Initially OK but Now Appalling
For several months thought Plusnet was ok and, I thought, reasonably priced but that soon changed when I started getting buffering when trying to watch TV. I supposedly had superfast fibre broadband 500 MB/s however speeds were regularly dropping to below 50MB/s. Also at the same time I was getting offered an upgrade to 900MB/s at a lower price than I was paying. I contacted Plusnet stating that I was interested in taking up the offer but would only do so if they managed to resolve the regular drops in service that I was getting. After 3 months of dispute, Plusnet were unable to provide a consistent broadband speed, would offer nothing by way in compensation for them failing to meet their contracted deliverables and then asked if I wanted to switch to the new 'faster' and cheaper deal. I obviously said No. I then moved to a different supplier who was not only faster but cheaper than even Plusnet's special deal. Plusnet then told me I would have to pay an early termination fee but after much discussion and me stating I would not pay it as they hadn't fulfilled their contract and as such had forced me to leave they eventually agreed to waive the early termination fee as a gesture of goodwill.
There's a lot more to add in that they said that they couldn't accept a drop in speed of 90% over WiFi at 5-10feet clear line of sight of the router as their fault, they were a low cost budget supplier who couldn't guarantee a level of service and would only accept a decrease in broadband speeds had occurred if measure via ethernet direct from the router. The other thing is their online support is appalling with them expecting their customers to use Twitter / X to contact them online with issues. No email and no online chat is readily available.
If you're in a small one bed flat and get a good deal then maybe go with Plusnet but if you're in a property that has multiple rooms or two storeys then avoid.