I have a new kx040-5 that I have put 8 hours on... it feels weak and jumpy compared to one rented a couple years ago. Dealer came out to operate and told it is running as it should. I wanted this size as i already have a 14k trailer and it will be used primarily on my small farm and hunting properties to dig a little dirt, clear brush lines and clear trails. To keep a happy customer, the dealer is willing take it back and bring me a kx057-5 spec'ed the same (except no 6 way blade) for 10k more than I paid for the 40. I do not have a trailer as I believe the 14k will be too overloaded. So, for all of you that has owned both, what say you, is the 57 worth 10k more? I have owned several small excavators in the past, such as Bobcat E50, cat 305, Yanmar 80. All of them operated as they should. Dealer tells me nobody has ever wanted to swap out their 40 for a 57, and sell 5x the 40 as any other.