I don't find the L4240 under-powered at all.In the winter (we get a fair amount of snow) I have an eight ft.Curtis FEL mounted snow-plow and a seven ft.rear...use both at the same time.I have an old Ferguson two bottom plow,it pulls that with ease,use a six ft. rototiller and bush-hog.
With the rears loaded(R1 tires) I have hooked rocks and lifted the rear..that's how much power this loader has.Like I said amazing tractor with this loader.
Did you find your l3130 that you traded to be underpowered?
I have 370# of cast on the rear wheels and that was not enough to hold the back down so I added 1200# on the 3pt which works great for keeping the back down but sucks the hp when I need to go anywhere. I am hoping the 4240 has enough extra hp to make the trade worthwhile.