We had a great experience at Halkova.
We were very well welcome by Mikhail. He picked us up from the airport for 20 euros (totally worth it) and helped us as we checked out.
The apartment is very well equipped and very cozy. Despite what we heard about Prague buildings, there were very efficient shades and the early sun did not wake us up.
The location is great as well, we never took a tram or bus in three days.
Overall everything was perfect, very recommended.