gellison: As others have mentioned, I too just purchased a new tractor which included comparison between NH TC40 & a JD 990 (both 2 liter engine size). While the 990 was a "stronger" tractor (everything, including the gas tank, was metal!) and "looked" more like a tractor, I chose the NH. Why? The 16LA loader has much better lift capacity than the JD (you didn't give the model they are offering you), much better visibility. The access for servicing is better. The hydraulic pump has better capacity. Etc. Etc. Further, the trans was straight out of the 2120 series (in use for almost 20 years). You might check the TC35 engine (out of the 1720 series?) to see how long it has been around. I don't know about the JD 4310, but the 990 uses a two stage clutch vs a single stage on the NH. Clutch replacement (worst case) on the JD was $2000-$2100 vs $1000-$1200 on NH. I believe the repair cost down the line will be higher on the JD. Overall, I respectfully suggest the NH is a bit more heavy duty. That's not to suggest I wouldn't be happy with the JD if somebody gave me one. Finally, the NH have certain anomolies-you might want to check the NH operation/serving section on this board for some common problems (as well as the JD section). Good luck with your choice. JEH