the niu Yen Mini-hotel

A very unpleasant experience!
We arrived before check-in time (3 hours), so we just left our things in the storage room and went for a walk. Unfortunately, the trains were delayed that day, and we returned to the hotel only at 11:30 pm. We were told that there were no more rooms, as there was "some kind of mistake". How this happened with a room that had already been paid for is unclear. Most likely, it was simply given to someone else due to the influx of tourists on popular dates.
Despite my objections, they sent us to another hotel 4 kilometers away from the original one. They called a taxi for us, the driver sighed the whole way because he had to drive us and because he would have to receive payment through the reception, and made us feel uncomfortable.
In the end, they checked us into a normal standard room, but in a completely wrong area on the outskirts, and wasted an extra hour of our time, which we could have been resting. And Holiday Inn Niu did not offer anything in return. Very disappointing.

There's nothing wrong with the hotel and my main gripe is mostly about the size of the room. It's terribly small and squeezey that I find it almost non-functional other than to jump into bed to sleep in. Also seems like the beds are only available as twins and they'll push them together if you ask for Queen, so groups travelling together should note you'll not have too much space away from your travelling partner especially if you need space.
The "table" is so narrow that it's almost not possible to work on a laptop on it.
The shower is also extremely small and I would think the typical Caucasian adult will find it depressing to use.
I've been to businessman hotels in Japan and I still find this to be less comfortable than those I was in.
There's no facilities to speak of, no gym, and I think it's the reason why they encourage you to work in the lobby where a proper big table is in place.
The saving grace is perhaps the breakfast which is satisfactorily European standard fare and good variety.
There's nothing in the nearby vicinity for essentials. I believe the nearest supermarket is about 5-10min walk.
Check in and check outs was fast and nothing dramatic, just don't expect anything warm or charming.

Was supposed to stay at this hotel. While on Google it says its in Hamburg, the website will direct you to the one in Stuttgart. Double check your booking. Only reason I noticed was because on the reservation confirmation they put the wrong name too so I called to correct it only to be met with the most unfriendly customer service.

When booking the room, I specifically asked to book a two single bed room.
I tried to call their service 3 times, with only German language and waited each time on the line, until the call automatically ended by itself. No information.

Rooms are mostly clean. There was a huge stain on the wall though.
The self check-in didn't work, asked to pay again. Then had to wait 15 minutes in line to check in manually, there was only one person working.
The service was mostly not so friendly, rather "straight to the point" and demanding, even arrogant. Didn't create a good feeling.
I had to explain I already paid for the service. The service told me that "all of our beds are queen beds" and no solutions.
Good price level with decent rooms but just the experience sucked.