I purchased a NX4510 with the KB2485 backhoe November 2015 and love it. As dumb as it was I purchased in the spring of 2015 a CK35HST with a KB2475 backhoe and decided I really wanted a cab so I traded. I had zero troubles with the CK but for winter I wanted the cab and everybody warned against the CK without A/C in summer hence the trade (and the dealer gave me almost full trade in value). Anyway, I love the NX and backhoe. I read somewhere on here how they wondered about the backhoe operation being impeded by the cab. I now can say that operating the backhoe you don't even realize the cab is there. I really liked the CK but you can definately feel the NX greater digging force and seems fairly significant.
The downside of the CK vs NX is the CK I could stand beside it and inch my way back over the sub frame. Once you do it the next time is relatively quick. The NX, not so much. Set the brake, neutral, get out, verify position, get in, remove break, put in gear, move to what you think will work and repeat the process over and over....I haven't tried going around the seat safety so I can work it like the CK by using your hand to inch it back onto the bh but I'm thinkin that is one mod that will ease the pain a lot..
I am going to have to decide if I want to buy the factory one or mod mine pretty soon, because I need to bury electric, water and cable tv to my shop. I bypassed my seat switch right after buying mine.
