</font><font color="blue" class="small">( Does anyone have actual experience using a Jinma/FarmPro to lift large round bales with a rear spike ?? )</font>
The answer depends heavily upon WHICH Jinma/FarmPro you're asking about. FarmPros are generally in the 18-25hp range, whereas Jinma are being sold up to 45 hp.
Extra weight and balance generally accompanies horsepower increases. More weight - and better distribution - means bigger bales.
I never even considered investing in a TPH spike for my JM254. Front ballast isn't a consideration either, because the rear hydraulics are only rated to lift something like 875 pounds. But I wouldn't have any problem buying one for my KM454. It's a good 1600# heavier, with twice the hydraulic lift rating.
//greg//