I have a commercial owner operator that just went from a 3710hstc to a 5030 this past year and all he does is say he's happy about the difference of power. He put nearly three thousand hours on the 10 series with duties of a front blade and provnost 78" pro blower fully hydraulic on the back in the winter for clean-up of his plow trucks, a harley double roll replaced the blower in the summer.
Some people, I most of the time over work under powered equipment or use it to it's fullest extent. I get as good if not better gas mileage with with a large engine then with a smaller one. You would enjoy the extra power of the larger one and with the extra weight and length it should handle a loader great although the largest they get is the 800 chassis for the L-series. If you feel you could use more power go for it!
Be sure you aren't sacrificing any other uses in manuverabilty because of the extra size for any of your work. It could be a good time to get an extra option or two!