S series came out in different years for different sizes. Most around 2000/2001. 753's lasted a year later than most, being replaced with the S-130. The little 463 just became the S-70 this year. In the S-series, add a zero to the number after the S to get Bobcat co's rated cap. So it would take an S-250 to lift 2500 lbs high overhead safely according to Bobcat, but I'm sure an S-220 would normally do it. Either of those is a pretty big skid steer. I like the boom set-up that the S-175, 185, 250, and I think maybe the 300 have. You know, the extra linkage so they stay in a vertical plane as they lift upwards. If you fill tall trucks or dig lots of post holes I'd say this is nearly a must. Condition is FAR,FAR more important than hours. A machine from a good home is pretty dependable up around 2000+ hrs, and I've seen 700 hr machines that were nearly JUNK. Personally, I would NEVER buy something with over 500 hrs if I couldn't talk to the previous owner. I have purchased 2000 hr machines when I got a good feeling from talking to the previous owner. If the machine is for constant, near daily business use, where downtime and reliability are really important, I'd probably stay under 1000 hrs. If for personal or occasional use, I'd go much higher hrs. if I had to. Bigger is normally better if size(workspace) isn't an issue. Right now I have 3 wheeled machines (Small, med and large) and a tracked machine(T-190). Early tracked machines--864 and T200--had lots of drive motor issues. Never get one of those. I'd get a kubota engine, whatever size/model I ended up with.