Cat D3 G and K

I will need a newer dozer before to long. Our old dresser td7h is getting wore out and tired. Would like to go with a Cat D3, and would like to hear what you guys think about the G and K series as for the controls for the hydrostatic drive and how they feel when pushing. I had one guy tell me that the g was ruff when pushing, he said it was jumpy not as smooth as a k. I want one that is smooth for finish grading. I will be looking for a standard track dozer. Thank you

Cat D3 G and K