Just got back from the cinema. Here are my thoughts:
-Better than the first, and has a much more cohesive plot this time, although I didn't particularly think the first movie was anything to ride home about so I'm not sure if this holds any weight
-Characters were expanded upon that were kind of ignored in the first one
-Lots of alluding to the security/freedom paradigms that will come into play in Civil War which I really enjoyed
-Dialogue is still cheesy, but Whedon learned from Assemble to tone it down. Some of it actually drew a couple chuckles from me admittedly
-Some of the acting and special effects were weak in a few areas, although it doesn't really effect the experience significantly
-The Maximoff twins were written poorly. Don't expect to be blown away by them.
-Ultron isn't memorable either. I mean, he's a serviceable villain, but you can't really empathise with his goals like you can with Loki. He's smart mouthed, but lacking in any sort of gravitas
-To compensate though, Vision is great even if he doesn't get a boatload of screen time
-Becomes a bit of a Michael Bay tier rooty tooty point and shooty fest nearing the end, although it's not as gratuitous, and the action is more versatile than just mindless explosions
Overall, I felt like I got my money's worth, wasn't as fedora tipping as I thought it'd be, and is definitely one of the stronger MCU movies despite not being able to top Iron Man 1 and The Winter Soldier. 7.5/10 from me.
I will divulge in spoilers if people want me to.