Overall - Thumbs up.
Tighter story than AoE. Movie has a good pace. Starts, shit jumps off, and keeps going. No lulls.
Lore WAS addressed in more depth than previous films. I wouldn't say it's Shakespeare, but it touches on and mentions a good amount of Transformers references from the cartoons and books.
The movie overall didn't have a ton of surprises; most of it we kinda pieced together by now. It was good seeing it all play out linearly though.
They did leave it open at the end, several points. We are jumping right into 6 with no soft reboot.
I like what they did with Lennox. It isn't as cut / dry as the trailers seem.
Simmons - Glad they found a way to keep him involved.
Megatron was handled very well. Welker's voice makes a ton of difference, and has life to it. He's calculating, intelligent, and has a newfound gravitas. Don't even get me started on the nigh perfect design of his.
The purple eyes on Prime, and the name he was given while in that mode, awesome.
Points I didn't care for:
Baby Dinobots - wtf, where, why, how.
If Quintessa created the Transformers, what's up with the Allspark.
The Cybertron attacking Earth bit. They had an explanation, then created another explanation for it to hang around, so that they could have time to stop the chaos. Unnecessary, didn't quite get it. They could have had it just be coming here to do the first thing, and then stop that from happening, basically the same way. All they had to do was remove and tweak a scene or two and it makes more sense.
Decepticons - It looked like we were getting some characterization and then nope. Actually, they were still better than past 3, but too short. Ultimately still cannon fodder in the end.
Bumblebee - Do not understand how Bee spoke. Unless he was playing a recording of himself from earlier.
Merlin - Merlin was Tucci. I have to eat my pants on that one. They did not connect it to Tucci's modern day character. Maybe down the road. That being said, if he does turn out to be actual Merlin from ancient times, living all this time, then Vivian's character could have been omitted since she was important because she was a descendant of Merlin.
And yes, taking a page right out of TF: Prime, Unicron is in fact Earth. They even have a picture of him and everything. The ending with Prime calling all Autobots back to Cybertron was REALLY cool and emotional for me. Finally, they get to return to their home, even it is wrecked to shit and floating in Earth's atmosphere.
Overall, it was a better ride than AOE. My personal ranking is the first movie, then DOTM. This is tied with DOTM in my opinion. I liked the visuals and action in DOTM better, but this is very close and had a deeper story. This basically feels like a big setup film for TF6 to springboard right off of.