We loved staying at Mario's flat. It was very clean, and had everything we need. The untensils were all new. There were three bedrooms with perferct beddings each and one small room with a big table.
The wifi worked perfectly with the network and password on the wifi outer. TV worked well also.
The location was not so close to the tourist sites but no worries. Ubahn is 7 mins walk and Vienna central station is 17 mins walk from there. The public transportation was so convenient so it was great.
I don't recommed using the lift though. We were stuck in there upon arrival but it was opened easily by force thankfully.
When I couldn't find the hair dryer, Mario brought one for us the next day.
Overall I strongly recommend this flat for your Vienna trip because you would never find this level of flat with this expence.