There's plenty of holes in it but I came in expectign that. I wasn't expecting strong Transformers characterisation or anything. Just expected a brainless, soulless 2.5 hours of action with some good moments. I think if you expected more you would be disappointed.
That's not to say of course you shouldn't expect more. But I guess in my case, I was resigned to the fact that I knew it would be average and disappointing so I lowered my expectations accordingly to reduce disappointment.
It's sad but it works. If I wasn't a TF fan I don't think I would've been disappointed b/c going in all I wanted was splash, bang, gratuitous T&A and slapstick. And the vast majority of my non-TF friends have all enjoyed it.