A better item is a better result
A practical method for evaluating an upgrade.
Keep one comparison stable
Compare equipment against a familiar enemy type or hunt. Changing the area, skill setup and equipment at the same time makes it difficult to identify the source of an improvement.
Look beyond attack
Damage matters, but so do time spent recovering, mana consumption and deaths. Green and red item comparisons expose trade-offs. A defensive improvement can produce more useful progress if it prevents repeated interruptions.
Recheck the combination
Set bonuses, sockets, class restrictions and two-handed equipment can change several slots at once. Inspect the complete equipped arrangement after the change. Keep a useful alternative until the new configuration has proved itself.
A simple before-and-after trial
Choose a familiar area, note the current supplies, then complete several encounters with the existing setup. Change only the item under review and repeat. The useful question is whether fights, recovery and spending improved together. One unusually large critical hit should not outweigh a pattern of slower kills or more dangerous recovery.
Keep the comparison reversible
Hold onto a useful alternative while evaluating a replacement. Favourites help distinguish those alternatives from the equipment intended for bulk disposal. Check class and level requirements, both hands, sockets and set thresholds before recycling the previous arrangement. Those interactions can explain why a higher-rarity item did not produce the expected improvement.