Welocme to TBN and the JD forums...I have a 4210 E-hydro with 165 hours on it to date. I have 10.5 acres, 5 of which is yard, and I mow ATV trails in the back 5.5 acres. The trails get really overgrown, but the 7-Iron MMM does a great job of rough cutting as well as lawn mowing.
Some people say the 4210 is underpowered but I have only had to use full throttle in low range one time, to drag a 3000 lb. slab of reinforced concrete to the end of my lot. Usually I run out of traction long before I need more power. My tires are non-loaded turfs, which may contribute to the lack of traction, but I am still happy with the tire choice as most of my operating hours are mowing time and they give rather good traction in snow.
I have a few minor gripes about my JD...the parking brake is weak, the factory toolbox is a joke, and I'd like to be able to change the oil and filter with the loader attached. But overall, I am quite pleased with my tractor.
About the FEL available for the 4210--the 420 is a very good loader and has ample power for my needs BUT I wish it had the greater lift height of the 430 FEL. Had I realized how much loader work I would end up doing around here I would have upgraded to the 4310/430 combination. Good luck !!