When you are looking to buy a home, it is critical that you have an automatic house search email set-up for you.  This is important, because it is a competitive market for buyers in Minnesota, and you need the information on the newest listings, as soon as they come available.  The best search in terms of getting the newest listings or those that have gone through price reductions, as soon as possible, is to have your Realtor set-up you up on a search pulling directly from the MLS.  This is something that only the Realtors can do for you.  When you have an email search set-up with the MLS, you get the latest listing updates as soon as they're available.  If you use other websites, then that information will be somewhat delayed, because 3rd party websites have to get their information from the MLS.  And they can only do that on a limited time basis throughout each day.  

However, some buyers choose to use other websites for their searches, because they prefer the interface, mapping abilities, etc...  If you are not using a direct-MLS home search, I would recommend that you use a real estate company website for your saved home searches.  You can also use the national websites (Zillow, Realtor.com, etc...), but some of them don't have the most accurate data all of the time.