Neil, perhaps I read the Kubota site wrong? I show the B7510 at about 145lbs less than the 2015, comparing 770lbs at the pins to 915lbs on the Mahindra. Now the 30HP Kubota B7800 does lift 145lbs more at the pins than the 20HP Mahindra, so you are a little ahead on that. Of course if we go to the 28HP Mahindra 2815 we are at 1410lbs at the pins, which is about 40% over your 30HP machine. In general, I think my statement is true. The 15 series Mitsubishi built Mahindras are heavier and lift more than the comparable B series. I've used lift capacity at the pins to be consistent, but you could use either measurement, as long as they are used with both brands. The BX is lighter than the B series and certainly lighter than the 2015 or the Kioti. Some applications call for less weight, so it isn't always a bad thing.
To the original poster, sorry to get off track here.