i just installed a network based system for my wife's boss,
he got 2 houses and 1 office in a city, but a branch far away in the East,
it was my 3rd time applying remote monitoring after diving into NVR from CCTV,
well, the performance is quite good and the bandwidth was sufficient for VGA realtime quality.
the equipment i used isn't a big brand, it's plustek slim something, different models with different part numbers i think.
pretty easy and the point is, the cost is not much
try it if you are designing for smaller scale and looking for a competitive price to DVRs.