We are a family with a young child and stayed in a private room & bath and our room was in the adjoining annex. The room & bathroom were very clean. The breakfast and dinner were fine considering the price is included with the room. The free walking tour was fabulous! We weren't sure what to expect and were delighted in how much detail we received.
The only "negatives" were 1) the free wifi did not work most of the time in our room & 2) the majority of the staff seemed indifferent. They weren't outright rude but not overly friendly either. Finally, they do offer a room to keep your luggage in before/after checkout that is supposedly monitored by video but I would not have felt comfortable leaving my luggage there with access to all with little to no monitoring.

Archi Rossi was an impressive hostel situated about easy 10-15min from the center of Florence, 25min to Santa Croce, only 5min from the main train station.
+++ Very convenient location, full of nice decoration (painting, sculpture, ...), clean, good staff, free or incl. stuffs like city tour, internet and breakfast, personal locker, personal reading lamp
+ Security level (they even ask to show the key every time you come in the hostel lobby
- I just regret they are not proposing some "nights out" but it did not disturb me!
o Even a computer in the bedroom, Small shower but enough, and anyway other showers in shared bathroom every floor

Recommended!

The location is good and close to train station. Staff are friendly and helpful especially Nora and the lady. The wifi cannot be detected in our room so we have to go to the internet area near the front desk to online. There are few computers there which is enough for the guest. There is room cleaning daily. Overall it's a nice, beautiful, and clean hostel.

Great location! Very easy to find and close to the sights and other commercial establishments. I stayed in a 4-bed private room. Quite spacious but the bunk beds are quite... short. I stayed in the lower bed and I always bumped my head in the top bunk. The room had a personal computer but the wifi was conked out from time to time so it was quite inconvenient. However, the hostel had computers that you can use for free in the lobby. Overall, the room was clean and it was kept clean.

Plenty of options for breakfast - but don't expect it to be filling. Hostel also offers cheap dinner meals. Staff is great too!