The spec I saw on that....553 loader...
JohnDeere 553 Loader Utility Loaders Material Handling Equipment JohnDeere.com
was only 2917lbs @ pins.
Deere muddys the water a bit (and others are starting to do it as well) giving a spec @ 59" lift. And yes it is much higher. 1000lbs higher to be exact. But that doesnt mean the deere will out-lift another tractor rated @ only 2900 to max height, because they ALL will lift more to a lower height. The loader travels in an arc. And the higher you go, the steeper the angle gets on the cylinder. Thus reducing its capacity. Kubota doesnt publish the "59" capacity" but just guessing based on the ones that do, the kubota is probabally capable of ~3300lb lift @ the 59" mark.
So I guess what I am saying is....when comparing loaders...BE EXTRA SURE you are comparing apples to apples. IE: Pins @ max height to pins @ max height. Dont try comparing pins @ 59" to Bucket center @ max height. This will give you false comparison.
Here is the info directly from the link you posted:
Bucket used General Purpose - 73-in. (1850 mm)
Bucket weight, lb. (kg) 392 (178)
Lift capacity at full height, lb. (kg) ---
Measured at pivot (U)
3133 (1424)
Measured at 500 mm ahead of pivot (V) ---
Measured at 800 mm ahead of pivot (V) 1956 (889)
Lift capacity at 59 in. (1500 mm), lb. (kg) ---
Measured at pivot (W) 4008 (1822)
Measured at 500 mm ahead of pivot (X) ---
Measured at 800 mm ahead of pivot (X) 2891 (1314)
Boom breakout force, lbf (kgf) ---
Measured at pivot (Y) 5378 (2439)
Measured at 500 mm ahead of pivot (Z) ---
Measured at 800 mm ahead of pivot (Z) 3604 (1635)
Bucket rollback force capacity, lbf (kgf) ---
At maximum height (VV) 3877 (1759)
At 59-in. (1500-mm) lift height (XX) 5544 (2515)
At ground level line (ZZ) 3860 (1751)
Also, Kubota does rate the loader lift capacity at 1500mm lift height (59") in addition to the full height spec. With that said, Kubota doesn't as readily post this info as Deere does. Some Kubota models they post this in the spec sheets, others you have to look in the owners manual. For example, they post the 1500mm specs for the
L4600,
L3800/3200, but I haven't seen it in the specs for the Grand L's or the Mx4700/5100.
Not trying to argue with you, just giving the OP another option.