Hey @Jason Thompson!
Generally I prefer Crexi from a visual and navigation perspective.
I completely agree with @Greg Kasmer and @Jasmin Hernandez
What has worked best for me to source deals is to use Crexi as a way of finding listings that roughly suit our acquisition criteria and contact the listing broker. If they list a property that is similar in geography, class, price range and # of units & or tenant quality its likely that they have more of similar opportunities as well.
I'll call up the listing broker, build some rapport and give them a run down on who we are and what we are looking for. After confirming that what they listed is something they transact often and it seems like their inventory might be a good fit we exchange contact information and I send over a clean document which outlines our acquisition criteria for their records.
I follow up consistently and promptly and continue to provide feedback on the listings they send until the trust is built and we find a deal that is a good fit. Then its time for an LOI and the real work begins!
Another recommendation I have is to also search for properties on individual brokerage websites following a similar process as I outlined above or finding brokers in your market and creating a personal relationship with them.