I attended the 4th day in Barcelona. It was a great experience even for me who has been to many GP's. 15 Euros for a day pass what entitles you access to any part of the track apart from the pits. I highly recommend it to anyone.
From what I could tell this season is going to be very close and interesting. Mercedes are very reliable but Ferrari have upped the game again this year in terms of performance.

https://www.youtube.com/watch?v=h1bfYJYYJvA Some of my footage from Thursday.