Kiso Valley or Ise Peninsula for 2 days?

I am trying to decide between Kiso Valley or Ise Peninsula for two nights to fill an otherwise 10-day trip that includes:
Osaka - 3 nights: arrive into KIX, day trips to Kobe and Kyoto (been to Kyoto before so one day is sufficient)
Nagoya - 3 nights (first time, may take a day trip)
Tokyo - 2 nights: depart out of NRT.

- Insert Kiso Valley or Ise Peninsula for 2 nights, probably in-between Osaka and Nagoya -

This will be my 4th trip Japan. On previous trips, I have visited Takayama, Kanazawa, Fukuoka, Hiroshima, Nagasaki, Osaka, Koyasan, Nara, and Tokyo, if that gives you a sense of the diversity of places I've already been.

Thanks for your help!

Gooday. For me (and may not be typical) Nagoya was a bit of a yawn, so I would be spending 2 of your 3 days on day trips including one to Kiso valley.

That would then free me up to do 2 days at Ise!

Which month are you traveling?

This could significantly change where you visit as I would really visit the Kiso valley in Feb due to the icy/snowy weather etc.

Also - what things do you like? Both locations are rather different. The Kii-Peninsula has lots to do but it's a bit too big for 2 days. Public transport south of the the Ise Shrines can also be slow and not that frequent. But then again - it can be beautiful.

Personally - I find the Kiso Valley looks best in later Spring April/May when the surrounding area comes to life.

thanks for your responses! and apologies for omitting the fact that i will be in japan in november 17-28, just a few weeks from now. and traveling solo.

based on responses so far, it sounds like kiso valley is perhaps better as a day trip from nagoya. and that ise is worth a 2-day stay due to its size and all there is to see there. i will not be driving -- just taking busses and trains -- and am wondering if shima peninsula may be difficult to do without a car.

do you think kobe is worth visiting for a couple of days (in place of kiso and/or ise?). i am also open to suggestions for other places to visit between osaka and tokyo not listed on my original post above.

Mfedley accidentally mentioned the Kii Peninsula but you should consider it.

Kobe is not a very interesting city. The Kiso Valley and Ise area are both much more interesting places.

You could definitely spend 2 days in the Kiso Valley. The valley consists of many former post towns from the old Nakasendo Trail that connected Kyoto with Edo (Tokyo). Many of the post towns have been well-preserved, so they have great historic districts. If you like hiking, you could hike through multiple ones in two days (and of course the trains make it easier to visit multiple places). Perhaps people are not recommending it because the area's attractions are mostly the historic districts but spending the night in one of the historic buildings would be very nice. They should serve traditional local food and a morning stroll through the historic area is probably pleasant. There are some natural sites in the area, too, though. There is an English website that has information:
http://www.kisoji.com/english/

The Ise area of course has Ise Shrine and Meoto Iwa, both very famous and well-known landmarks. I don't know why it has such a low rating on this site, but I found Kumano to be a really nice place. You can do a hike through one of the former pilgrimage routes (the Matsumoto Pass) and then visit the World Heritage Sites which are quite interesting:
https://www.japan-guide.com/e/e4959.html