I just returned from the park. I haven't been for many years and knew much of the park would be under construction. I was surprised it wasn't as bad as I expected.
Yes HP is a huge construction project, but it is pretty much hidden behind a wall at the front of the park. Despicable Me is on the far other side, and you can't really see it unless you walk to the end of the London area. The only part that felt cramped and "in progress" was the Simpsons area, especially trying to get to the studio tram area because there are construction walls on both sides of the walkway.
Hopefully the Simpsons work will be done by May, but if not it is still manageable and didn't really distract from my enjoyment of the park.