Buying Advice NEW 2015 Bush Hog Razorback BH6 VS USED Bush Hog SQ172

[NorthernChill]

I ran across two very good deals. One is a Brush hog SQ 172 (with shear pin) that is used but in good condition I think it is 2010 or 2009 , the guy is asking $1,000 for it but last time I talked to him I got him down to $800 or $850, the other cutter is a 2015 Bush Hog Razorback BH6 (with shear pin). I got the dealer down to $1,199 plus tax of course. I have 10 acres and 4 acres are covered with weeds and thick picker bushes about 5 feet tall, and 3 acres are covered with 3 to 4 feet of grass and light weeds. I was wondering which mower I should go with? Please let me know what you think or if the 2009 Brush Hog would be a better cutter