Place was really okay, about 10-15min from city center as it is really close to some of public transport lines. Me and my girlfriend didn't actually see Niko at all in two days of our stay, but it expected since we spent really just short period of times in apartment.
If you are in some city, guess it's your target to explore it and see as much as possible :)
Apartment was nice, Prague is beautiful and that's all folks, enjoy your stay in town!