My Kubota is in excellent shape mechanically. Got some sheet metal dents but nothing serious. It needs nothing. Tracks great, Bushings a little lose but not bad for 2000 hours.
As far as a 160 machine? My inner child wants one just to have one but realistically i would not have much work for it right now. The 8 ton machine would be something I can use right now. I could bolt the mulching head on it but I am always having too cross pavement and concrete on my jobs. I do very little new construction so the that is just they way it is for me.
I will add that 160 class machines here hold there value. To get a 50k dollar machine I would have to get a 10k hour machine or something in the 90's. Most will not have a thumb and many of the older ones will not have an aux circuit at all.
Essentially in my cheapskate mind I can have 2 machines for the price of one and I am having a hard time with that. Also take into consideration that my machine spends 90% of it's time digging trenches and mulching so that is what the 8 ton would be doing. I dig Miles of trenches a year and I cannot imagine the 8 ton machine not speed things up over the 5/6 ton machine.