I thought Plusnet had closed down Metronet years ago, I used to be with Metronet and was so annoyed when Plusnet took them over I went to AOL for a month
I never wanted anything to do with plusnet then.
Now I am with plusnet I can understand why I did not want anything to do with them.
Are you going fibre or staying with ADSL? Either way you will find all the larger providers like Plusnet cheaper than the smaller ones like Zen. but you should get a better service from the smaller providers.
As RobertoS typed, it depends on your usage, if you been with metronet all this time I presume they was still using the PAYG system or did they get rid of that?
Plusnet and Talk Talk are two of the cheapest ones in the large providers, also have a look at Vodafone if it is available where you are.
Desktop machine now powered by windows 8 pro 64bit, no dreaded metro and Linux , laptop by Linux