The good:

The location is nearly ideal - a short walk to I.P. Pavlova metro and tram station in one direction, and a slightly longer walk to the Museum stop which is just across from Wenceslas Sq.

There is a Tesco Express around the block making it easy to get food and beer.

There are basically 4 single beds that might be arranged as 2 doubles or a mix of double/single. However, the place is small enough that 4 individuals staying there would feel cramped. Also, mattresses were very firm

Overall, reasonably clean and comfortable enough (some cobwebs by the ceiling, but floors/kitchen/bath was clean).

The less good:

The curtains are thin and even with thick windows there is some traffic noise, so I found a sleep mask and earplugs helpful.

The wash machine doesn't dry, and there are no racks or lines to hang clothes.

The wifi is indeed flaky - Jan worked on it but it was frustrating. Possible in the evening to pick up the one from the cafe downstairs if you've gotten some drinks and their password.

Better to bring your own bath towel - as others have said the ones provided are small and stiff.

The shower hot water pressure would sometimes fail (likely someone else in the building closer to the source).