Only you can decide that. In my case (4310 vs. 4410, extra $1800) it wasn't. I'm mainly flatland here and I've got farmer friends that have everything including articulateds so it wasn't an issue.
In your case (assuming you have a budget) it will come down to more power or more implements. If you have no budget then go big. /forums/images/graemlins/smile.gif