Not really. Most of the sites that make you give a credit card number for a free trial, (free if you cancel it in a week) are super dated. I have people coming to me all the time with huge printouts from those sites with expired, sold, and incorrect listings.
Buffalo/Niagara homes is pretty accurate and up to date.
http://www.buffaloniagarahomes.com/static/
Almost everything that is listed is part of the “MLS” or multiple listing system. That is basically the database for buffaloniagarahomes.com. RealtyUSA, Polis, and Hunt are all MLS based as well.
I work mainly as a buyers agent in the REO/foreclosure department at RealtyUSA. I also do a lot of preforclosure work, and I have usually access to properties before they even come on the market.