I was traveling with a group of 7 high school friends following a wedding near Prague. First off the location could not be any more central! Every time we got lost wandering the myriad snake like alley ways in the old town we seemed to come back to the flat. So if you're out to explore, then it's a great base to do so from - just be warned that there is no such thing as peace and quiet (which might explain why the neighbours are very prickly..)
The door to the building can get lost amidst the many small shops in Karlova, just round the corner from the Apple Museum. Don't be disdained by the dilapidated foyer as you come in, or the ancient steep stairs as the flat itself is rather plushly appointed and everything is new. Unlike other AirBnBs I've used, it was very clean upon arrival and well stocked in all linens, etc. The stifling heat could be an issue as I couldn't figure out how to speed up the ceiling fans. You can open the window to cross ventilate but prepare to appreciate the sounds of street level. Both bathrooms are large and will suit the needs of big groups/families. We didn't have need for the washing machine.
Communication is handled well and it becomes apparent when you go to pick up the keys from the central office of the host company. It's a slick affair and duly they provide you with all the tips and tricks the sort travelers look for. They have a handy map for example.
I'd certainly recommend - especially for those who only need a comfortable centrally located place to base themselves out of while they do tourist things all day and maybe night long.