Below you can check out the reader's thoughts, with a few spoilers present.
Dinobots were BARELY in it. They are in the last 15-20 minutes of the film.
The film starts during the Dino-era, and shows Lockdown blasting the Earth with some beam that turns living creatures into Transformers (over time). Then, the Dino's aren't seen again until closer towards the final battle.
There is a new Transformer built by humans, but they used pieces of Megatron's brain; so we know he'll be back in the future again. They practically uploaded Megatron's brain into a ton of Transformers (made by humans). The main human antagonist is working with Lockdown to eliminate the remaining Transformers (Autobots) on Earth, and Lockdown is trying to find and capture Prime for his collection.
There is an entire rescue sequence to save Prime on Lockdown's ship that was pretty sweet. There are Transformer dogs in the ship as well.
There are new Transformers... One is voiced by the guy from Godzilla, Ken Watanabe (Drift). His voice stands out VERY well. These remaining Autobots don't quite get along too well, but they do for the cause.
Lockdown leaves, thinking he has Prime. Once he realizes he doesn't, he returns for the final battle.
Same ol' FX, Same ol' Slo-Mo.
The story is very plain. Typical. No real twists, but Mark Walhberg has some awesome human vs human and Transformers sequences. A very boring love story between Mark's daughter, Nicola Peltz, and her boyfriend race car driver, Jack Reynor. I still prefer Megan Fox.
There's no real 'conclusion' to Megatron's brain being uploaded to other Transformers. It's left very open. The story focuses mainly on the human antagonist and Lockout.
There is NO mention of any of the old characters. Absolutely none. Not Sam, not the soldiers, the government agency guys. It's like they pretended they didn't even exist. Not even the Autobots made any mention of them... They practically took a sh-t on 3-films worth of development.
I really didn't think it was all that good. Not as good as the first. About as entertaining as the 2nd or 3rd film, but it doesn't hold its ground as anything spectacular. Nothing new... But they are definitely opening the door to a new trilogy.
OH! Big Spoiler here BTW:
The Dinobots are basically freed by Prime, and they go on a mini-rampage. Prime defeats one of them to "prove himself," and then the Autobots ride the Dinobots into battle... It was very cliche.