I think the PL is in danger of these extremely tight relegation battles being the case now for many seasons. Usually you'd have one or two basket case clubs stinking up the division like Sunderland or Aston Villa that get battered every week, but that isn't the case this season, every team from 20th upwards is equipped well enough to have a genuine chance of safety, and each club has been able to invest enough in the window just gone.