Switched from Shimano 105 calipers to the XG4, because i had always issues with the 105er, probably leaking. I switched pads plenty of times - original Shimano with and without scinted metal, changed discs, burned discs with fire, used 100s of ml of IPA, always with very very limited success. In the end, the pad's also added up at lot ... but the sound of braking was so aggravating.
Now with the XG4 - the bleed process is much more involved than Shimano's, because the bleed port has no opening/closing screw, so it will leak oil after disconnecting the hose (watching a Hope RX video that seems to be the norm). I also needed to buy a bleed screw set because my previous Bleedkit set did had no compatible available.
Long story short, now the brake performance is much much better, a little squishy in the first like 30% (what others describe as less "bite"). It might also because my first bleed process was not that great to be honest, after watching a vid from Hope RX I would need to do things a little different. But anyways, still great performance after like 50% lever pull, being able to block the back wheel and slide again (was not possible with Shimano). Already like 2 months, a couple of hundreds km, my Shimano's would have degraded already at this point.