Let's start with the things I did like. I was a little concerned that it would be overly theatrical, but after an opening video (90 seconds of Omar Sharif), and despite the fact that some of the staff are expected to wear Pharaonic headdress, there is very little overtly contrived in the presentation. The objects are laid out in reasonably spacious and well-enough lit galleries, and the numbers admitted kept to reasonable levels. So there aren't many jams (except at the beginning, where they keep you waiting before admitting you and letting you watch the video), it's never impossible to get up close to a case, if you're prepared to wait, and only occasionally is there not a clear route through the exhibits, leading to confusion as people try to go in different directions. I particularly appreciated the repetition of labels in large print on the tops and sides of cases, allowing one to read about the contents even when there's a crowd in front; other exhibitions could learn from this. Those labels seemed to me concise, and informative (though my companion thought they were dumbing down).
I liked the opening galleries, that set Tutankhamun in context, by displaying objects and images associated with his predecessors in the Egyptian royal family, to whom the boy-king was clearly related (though the exhibition makes clear that exactly how is still up for debate). And it was a bit of an eye-opener how many of Tutankhamun's own objects emphasize military prowess, and victories over the Nubians to the south.
That said, the exhibition is slightly disappointing. None of the really famous Tut objects have travelled from Cairo - no chariots, no couches, no sarcophagi, no death mask (the image used to promote the exhibition is actually a miniature coffin for the Pharaoh's viscera). Contrast this with the impressive centrepieces of Hadrian - the Sagalassos head, the Beth Shean bronze. And there's less than Hadrian - I got round in an hour, whereas I'd allow two for Hadrian (the first time I went it took three, but that was reading everything and listening to all the audio guide).
And there's a certain lack of purpose. Hadrian categorically sets out to educate the visitor about Hadrian, and to change their mind about some things they may have believed. Tutankhamun and the Golden Age of the Pharaohs doesn't have much more of a purpose than showing off some nice (if minor) objects from Tut's tomb. The labels convey concise information, but there's not as much to get your teeth into as in Hadrian.
All of which might not matter so much were Tutankhamun and the Golden Age of the Pharaohs not significantly more expensive than Hadrian. I'm still glad I went, but it's far from being the most impressive exhibition I've seen.