This was a must for us during our 2017 Thanksgiving trip in Toronto and it definitely was no disappointment.
The museum has an AMAZING external architecture --I loved it! On the inside, it's not different from any other big city museum. It kind of reminded me of the Field Museum in Chicago. Not bad, but not life-changing.
We decided to do the Vikings exhibit, which was at an additional charge. To that effect, I have to say the museum is quite expensive --the general admittance + the Vikings exhibit amounted to a good chunk of change, and we're a family of 5... so you do the math.
The Vikings exhibit was ok --just like that... lower-case ok. Layout was ok, content and artifacts were ok... but nothing in the exhibit blew me away. I could have lived without seeing it, to be honest.
After that, we did spend another couple of hours in the museum, and we had a good time.
Unless you're sure the additional exhibits will blow you away, just do the general admission.