I am not sure how much you're paying for Cerulean, but in my experience it was a good value for such a good location　(3 min walk to JR station), decent room / service, and cosmopolitan ambiance.

If you're into luxurious experience, or simply interested in comparing same brand across countries, go for Mandarin, it's really a great place, but IMHO it's not worth additional $100/nt, unless it's just one-night stay. Spend that money at Midori Sushi.