Just finished a 2-night stay here. Haven't stayed at the Andaz before so can't give any comparison points with that. Used a SUA to upgrade to Corner King Suite for 50,000 points total.

• Using exit 2A off the Hibiya line Toranomon Hills exit will get you here very easily without needing to leave the station at all
• Breakfast is good, and I rather like the portion given that it's a small buffet + one entree + one drink. The entree is a very small size but then you tack on the buffet and you should easily feel full.
• Suite is pretty good sized, layout is good given pull out doors to separate the living room, bathroom and bedroom, and bedroom sitting right at the corner to get the view. Unfortunately you don't get to see Tokyo Tower at all though, not even a smudge. Water dispenser right in the room makes it easy to not bug FD constantly for water bottles (not like it really matters though in Japan since convenience stores are everywhere)
• Lounge is on the 11th floor and open 24 hours I believe, and we used it after checkout before a midnight HND flight to do one last shower + re-pack our luggage after some more purchases. Not to mention if your room had no Tower view this is a good place to see the Tokyo Tower
• Service is good from what I remembered, but feels that the FD has folks more OK speaking English (and understood most of my requests) while the kitchen staff for breakfast seems like your typical Japanese-hotel staff who "knows" English but can struggle here and there

Some cons though

• Like another poster has said there's a distinct popping noise in the ceiling and walls that happens throughout the day. At first I thought it's just my suite so I asked about it, then they changed my room (from room 233 to 433 so same layout), but I still hear it although at a much lower volume and frequency. If this is something that can bother you (sleep or otherwise) then maybe get a white noise machine or something
• they completely forgot about our breakfast order on the 2nd day and so we waited 20 minutes until we called them just to realize they dropped the order, so that kind of just ate into our morning travel time

All in all, I like the hotel, and although the location itself isn't too enticing (not much in Toranomon Hills itself) I do like how it's pretty close to the station and it's just a 45 min train ride to HND. I'll probably come back again.