Definitely the 52" rear discharge/mulching deck. I use two of them year round with now difficulties. That deck has made mulching a reality. We don't bag anything anymore and have had zero complaints for the two seasons we have used them. My first Super B came with the 60" SD deck and I did not care for the cut quality or having to deal with the discharge. We always had to double & triple cut to get things to look good. Now with the 52" decks we typically only have to make one pass and we don't have to worry about blowing grass into beds and such. Really sped things up for us. We also run a couple of MB's with the 48" mulch decks too. Both are incredible machines. We are located in MD cutting mostly Tall Fescue similar to what you are doing in NY I believe. Go with the 52" deck and if you don't like it I have a 60' deck with about 300 hours on it that I would trade or sell to you cheep!