Cky has this bang on the money. I just got back from the cinema and thought the same things on every point. Yes, it had some funny lines but it went way overboard with it. And those twins? First, who the hell are they, and second, why weren't they destroyed? Awful.
The best bits for me were:
Every exchange between Megatron and Starscream
The opening chases/fights
Optimus vs Megatron, Starscream and whoever the other Deception was ("I'll take you all on!!!")
Constructicon (I assume that's who the multi-bot was)
Jetfire (the only one with a personality)
The prologue in the past, solely because it made me think about Beast Wars
I switched off a lot during this film, which is a ridiculous thing to happen in a film about giant fighting robots who can transform into stuff. Well, allegedly. Not a lot of transforming actually happened. Too much human waffle again.
I'd give it 7/10 as well.