First the love part, Zillow has useful information for buyers and sellers, mortgage information and even home design. Before being an agent, Zillow was my go to any time I wanted to look up a house or see a "zestimate." It is also great tool For Sale By Owners to get their property some traction. Again, Zillow is a great tool to skim the market but to get into the bitty gritty I suggest working with a realtor.
Now that I am an agent I can share the dislike part of Zillow. First the zestimates are not always correct. To get a true property value of a house, speak to an agent. Here is the best part.... an agent will do a market analysis for free! A Zestimate is just an algorithm so why not leave the estimate part up to the professionals.
The other part is Zillow has incorrect information. Countless times I have had properties sent to me from Zillow that were not up to date. Even though Zillow shows it is active, I will check in the MLS and the property is either off the market or sale pending. The best way to get the most up to date listings is through the MLS. Sometimes Zillow doesn't even have all the listings. It can be frustrating for those looking at homes that come across something they love only to find out it is already off the market.
Lastly, the agents shown under homes for sale are not the listing agents, this is misleading. The agents shown are paying a monthly fee to be featured.
Remember if you want the most up to date information on property or what is happening in the market best thing to do is work with a realtor!