best source for info on plus 5 units?

[Patrick Britton]

what is the best source to get information on commercial properties like complexes, apartment buildings, and plus 5 multi-families?  

and please, if your answer is Zillow or Redin don't bother replying.  what about Loopnet?  any feedback on that?

thanks! 

[Bryan R.]

Costar is probably the best resource available for commercial, but it is pricey.