I am not convinced those are the legitimate weights for approximately the same stuff. That is a big difference. It would be nice to be able to kick the tines at a dealership which probably won't happen.
I agree. The weights seem pretty far apart. I would expect the Land Pride top of the line (for the size) to be heavy, but I was surprised to see the 647 rated as "commercial" and so light. It weighs less than a lot of the "subcompact" tillers.
If you are considering tiller work on the side I would go with a forward rotating model. The 647 is a forward rotation tiller. The forward rotation tiller will climb over rocks, stumps and most buried debris. A reverse rotation tiller will hook under these obstructions and can be damaged.
Tilling and mowing for the public can be expensive for you if there is buried debris or booby traps.
I figured the 647 was forward rotation, since it wasn't listed as reverse rotation, on the JD website. Those are valid points for for going forward rotation. I can always go over it, again, to cut it more fine, with a forward. With reverse, it looks like it's just pulverize or super pulverize. Reverse may not be the best, since I will likely have customers with varied needs.
I have a 673 tiller and have used it for seven years now with good results. I would suggest that the 647 tiller would be a good match for you. If you can get one for $1500 or less in good condition I would go for it. All the pastures and jobs I have posted have been tilled with the 673 and that adds up to quite a few acres of hard packed soil.
Is the 673 the same series of tiller, just wider?