We loved our stay at Daishinbo and our day doing the Dewa Sanzen temples.
The staff were very friendly despite speaking no english, our food was exquisite and the facilities very nice. Our meals were not vegetarian as they contained fish but this wasn't a problem for us.
The bathrooms are Japanese style and segregated but as we were the only ones staying on the second night my wife and we able to use the facilities together.
Note that if you stay on a weekday outside of July and August it's not possible to get to the 2nd and 3rd shrines without your own transportation. This wasn't really clear tonus. You should also look into luggage forwarding or storage in Tsuruoka if you wish to do the full hike.More