I've stayed at the Park Hotel on business a few times (as recently as july this year) and cannot praise it enough. It is my favourite hotel in Tokyo for the price compared to facilities and service received. From last year there has also been the added bonus of a natural english speaker at the concierge and he has assisted me on numerous occasions for things to do in my spare time. I had a weekend there this time and he suggested numerous places in Shinjuku and Roppongi for me to check out. I would never have found them on my own, extremely helpful. I've always enjoyed going to Tokyo but now having that extra help makes me look forward to my next trip even more.
The hotel is clean, comfortable and all the staff friendly. I can not recommend this hotel enough.