Advice on Exmark Ztr

I have been using an exmark Viking for the past couple years and have about 15 lawns all pretty open, and have been turning down new customers due to the fact that I am too busy and can't keep up with the mower I have. I have been contemplating upgrading to a Ztr and think I'm going to finally make the move and purchase one so I can pick up some more lawns. However, I am unsure which lazer z series to buy, either the e or s. The X looks a little too expensive and unnessecary for my use. I would like to be able to save some money and buy the 52" e series lazer but want to make sure that I will still get a good cut quality and good performance but will definitely change to an s if the e is lacking good cut and performance or has any other reoccurring problems or if you see anything with the s series that makes the mower much better and worth the money. Any information/ feedback is greatly appreciated. thank you!