What can I say? This was a complete and utter disappointment. I have probably been to over 100 shrines in my time in Japan and I'd rank this at the very bottom.
First of all, what is so special about this shrine? Why is it one of Shinto's holiest and most important sites? It is supposedly home of the Sacred Mirror. Also, it was where Abe took the G7 delegation and taught them how to pray.
There are actually two main sites tourists visit: Geku and Naiku (the main site).
It is at the main site where the Sacred Mirror is reportedly kept. Now, visitors aren't allowed to enter anywhere. All you can do is walk up the gravel path to the entrance of the Inner Shrine. There, people can stand in front of a curtained gate to pray. Beyond that first gate is just a 'lawn' of pebbles. Photos are forbidden (although they don't make it so obvious). In short, there is absolutely nothing to see. Most local people seem to just go up and pray and that's it. To quote my Japanese girlfriend when we got to the focal point of the site: "This is IT?!"
Furthermore, and this is the same for both sites, all the buildings are rebuilt every 20 years. I believe all the interior goods, except for the mirror, are also replaced every 20 years. As such, everything looks brand new. They lack any decorations or anything to make the buildings remotely interesting. They could just be new onsen buildings.
Sure, the woods are beautiful, but in winter many trees are bare, and there is nothing unique about these woods. Many other shrines are in equally, if not more beautiful, surrounds.
I guess if you are a hardcore Shintoist, maybe this is an important pilgrimage site. If you are a tourist, I'd say you are missing out on nothing. Especially, if you only have a short stay in Japan, you'd be better off going elsewhere. Mie is a gorgeous prefecture, but for tourists with limited time, it doesn't provide a good return on investment (low bang for you buck).
The most enjoyable part for me was eating the different street foods and getting some local craft beers in the shopping street near the entrance to the Shrine grounds. We were also lucky enough to see the opening ceremony of a dance performance.