The X300 series of John Deere's are excellent mowers! The step up from the E130 would certainly be noticeable, especially in the frame, steering, deck and engine performance. While you are paying a premium price for the X series, you will end up with a better machine, one that will also last you longer. Unfortunately, while the transmission in the X330 and up are a bit more robust than the one in the E130, you don't get a ground engaging capable hydrostatic until you get to the X380. So, keep this in mind if you are at all considering pulling any loaded trailers up that grade you have, or using a dethatcher/aerator, etc.
FYI - Lowe's return policy requires your mower to be in "like new" condition which will require a Manager's approval to process the return. I got stuck in a situation where I had a mower with 1.5 hours that a Manager still would not return after I had been verbally told over the phone by a customer service person that I could return.