Knowing the hotel is literally under a railway, we expected it to be quite noisy from trains. They run very regularly during the day but stop around 10pm and start again around 6am...so it doesn't affect sleeping. It's quite a rhythmic sound once you get used to it!
Otherwise a lovely, modern, well-appointed and spacious room for our family of four. Perfectly located to explore Akihabara...and obviously conveniently close to train stations!
If you don't mind a bit of clickety-clack overhead and plan on only using the hotel to sleep and shower, you will love it :)