Ueno as a base for one week in Tokyo?

I have booked Mimaru Tokyo Ueno Inaricho (Google Map: https://goo.gl/maps/kZgBZrbDYK6ZZZ8a7) for the final 6 nights of our stay in Japan. Is there any reason to consider splitting time with accommodation in another area of the city? I don't think there is because train/transport links are great, but I just wanted to get input on this.

I did not include a capsule hotel on this stay. Is it worth spending our last night in one of those I wonder? Do they have higher end ones that offer a more special "experience"?

Earlier in our trip we are staying in more traditional accommodation in Kyoto (Kyomachiya Hotel Shikijuraku) and Kanazawa (Sumiyoshiya). This Tokyo accommodation seems like a good balance. With the kitchen we can make things a little more interesting.

Thanks in advance!

Ueno is okay. You could get on a train easily for majority of the must see spots in Tokyo.

Ueno is a great base to explore Tokyo for the exact reason you already mention - transportation links. I also visited the exact accomodation you booked in Ueno when a friend was staying there with his family. Very decent and comfortable place/room. Enjoy your time in Japan and also Kanazawa - one of my favorite cities in Japan.

Mimaru is a brand new apartment hotel chain which receive highly rated reviews everywhere. Since it is not a hotel, it does not have restaurants, and the service should be limited, but it provides wide room (as for the price, of course) with kitchen and laundry machine. It is not for everyone, but I think many tourists will satisfy, as the reviews show. I think you made very good choice. No need to change hotels.

Ueno is rather downmarket, and parts of it are quite sleazy, with touts who follow you around trying to get you to go to strip clubs. I'd be pretty depressed if I had to stay there for almost a week.

Yes parts of Ueno are quite sleazy but I have never found those parts too hard to avoid. The hotel the OP has linked is not too close to those areas either. I wouldnt split my time because even thought you would be in the same city you would still lose a chunk of the day moving hotels. I would suggest that time would be better spent on a day trip to Kamakura :)