The apartments are in a very quiet part of Mala Strana, not far from the Norwegian Embassy, and a very manageable and straightforward walk from Malostranska metro station (you can even get a tram between the two if needed - I didn't)
The apartment interior is really nice, an although there is no formal reception, the instructions for entry to the building and picking up room key were clear.
I had a minor issue with my room safe but, via a quick bit of communication with Petra, this was soon resolved.
Petra runs a very tight ship, and manages to sit on many chairs (as they say in Prague, apparently).
I would most definitely stay here again. I've been to Prague a few times and it's not every place I would say that about.