Thank you all for the replies. This is my first time to post in this forum and I appreciate so many useful advices from experienced travelers such as you..

I am using UA 50% certificate and was quoted Y16000 per night for two adults. I know this is a bargain after the 3rd person additional charge(was quote Y20000). I think I will pay the triple room rate for a more comfortable sleep if I decide to stay at Hyatt.This is my first trip to Tokyo so I don't want it ruined by bad hotel stay experience(get caught or get back pain in the morning). Park Hyatt is way to expensive for me even with the certificate(~Y50000). Another reason I like Century Hyatt is it's more convenient for us to take the ODAKYU HAKONE ROMANCE Express to Hakone national Park. Maybe we can enjoy early folliage there.

Another hotel I am considering is Crown Plaza in Ikebukuro. Rate offered: Y 12250 for three adults. Another bargain right? Not as luxurious as Century Haytt but is also a high quality property. Also close to JR station but I have to take JR to Shinjuku first to transfer to the other line to Hakone.

Thanks again folks...