Well, I am not really in the backhoe market that much now, but in the late 90's, I needed a newer backhoe to replace our 500 SuperK because of all of the new utility work we had. We demoed a 426C Cat and a 580 Super L Case, each with about 1500 hrs or so on the meter, and comperable price. Wed worked the 2 machines side by side for a week, and the Case was the clear winner by a large margin.
Here are some of the things I found:
The Cat did not have enough pull with the extendahoe to use it in the digging cycle, while ths Case would pull through harder material with the extendahoe, allowing a longer dig with each set up.
The Cat struggled to pull itself up onto a large muddy pile with its hoe, and did not have enough power for the tires to assist., I parked it, got the Case, and it pulled right up onto the pile.
The spec book says the Cat had more lifting power, but when setting 36" RCP, The Cat could not pick it up at the required distance to set it in the ditch, but the Case would, although barely.
We brought the Cat and Case sales rep out one day and ran a side by side dith digging test, with me on the Case and my top hand on the Cat for a half hour, then we swithed machines for another half hour. We were digging in Nevada hardpan, 24" wide, and 3' deep. At the end of the hour, the Case had dug about 25% more ditch.
We bought the Case, and a few years later, needed another hoe, and we got a really good deal on a 426C, so we bought it in spite of our good experience with the Case, which had not broken down, save a hose or 2.
The Cat went into the shop at 2500 hrs with a blown rear diff, and worn out brakes. At 2800 hrs, the e-stick broke in half, I am told by the dealer this is common???? and Cat has an updated replacement we can buy (no warranty on our used machine) 200 hrs later, the loader frame broke in half at the cross tube. also needed 2 new swing cylinders. at 3500 hrs, the brakes were failing again, loader arms were cracked again, and we were generally dissatisfied with it.
I just sold the Case with over 7000 hrs on it, and it has had a starter and alternater replaced, a few hoses, and a front planetary fail due to lack of lubrication (Oiler didn't put oil in it)
This machine was used even harder than the Cat, because we new not to use the Cat very hard, as it was always breaking down.
I will probably be in the market for a backhoe again, and it will be Case all the way.