In broad terms the Grand L (40, 50, 60 series) are more luxurious Ls. With a bit more lift and capability as well. The MX is the next model size up.
The L4802 (current model) or L4701 are top end of the L range. They are similar price to the bottom end of the MX range. The MX is more capable. If you want to do a certain amount of lifting or work, the MX will generally do more than the L. If you are weight or size limited, but need a lot of HP, the L4701/L4802 makes sense. But the bottom of the next model up is usually better buying than the top of the model down.
The Grand L is really a luxury choice, not a value choice. And I'd probably buy it if I had the chance, because it's a great machine.
Anyway, nothing wrong with the L4701/L4802. It's a good and capable machine. We're just pointing out the other models around that price point that you should take a look at to make sure you're making the right choice. If you like a bit of luxury, the Grand L may be better buying - it has luxury and a bit more capability for similar money. If you like more metal for your money, the MX may be better buying. But if you want the most power you can get in an L-size machine, then the L4701/L4802 is it.
For reference - are you doing tasks that require a lot of HP? That usually means blowing snow or running a PTO driven rear implement. Other than those tasks, the L has difficulty using all 47HP.