I normally have good experience in Kent House and their studio apartments. However, this week when I booked only the more "basic" studios were left and on entering the studio, I could see that the dishwasher was fully loaded with dirty plates, cutlery and cups and had not been turned on, the oven tray in the oven had a pool of very stagnant grease/fat left in it and the smell coming from it was pretty bad, the glasses in the cupboards were dusty and dirty and the previous guests bowl and cups were just left out. There were no dishwasher tablets provided, so I couldn't use the dishwasher to clean it up. Not sure what happened this week, but I feel their cleaners were having a bad day or just couldn't be bothered (which kind of makes the rule of no late check-outs a bit redundant if they need the time to CLEAN!).
I contacted AirBristol after doing the cleaning myself as I knew at that time in the evening I wasn't going to get a cleaner or another studio, they agreed to send a cleaner to re-do the cleaning the following day, but I wasn't to keen on that, and they agreed to refund the cleaning fee for my booking. I think they just need to give their cleaners a check-list of things to do (if one doesn't exist) to keep quality consistent.
I would recommend in staying in one of the nicer studios AirBristol manage which have a bit of colour and character to them rather than the basic ones they manage. The basic ones are OK if you don't mind bad sound proofed windows and blinds that don't really fit or block much light in the morning (would recommend getting curtains).