Ran into what I thought was an odd issue last night. On the weekend I acquired the shoulder item from the fire fight mission. Wearing it in GMM I skilled it up to 15% on the first tier. Then the other night I got the ring. So here is the issue, equipped ring @0%, shoulders @ 15% , and T1 boots @45%. Then ran through the first GMM mission. During the mission I monitored the skill ups. The shoulders did not change at all UNTIL the ring reached 15%. Then they both increased, boots are different tier so seemed to work fine. At the end of the mission, my ring had gone from 0 to 22% , the shoulders from 15% to 20%. I know they evolve using shared exp., but this just seems weird.
They no longer share xp. I have actually never seen them not gain the same xp. And I have leveled items on 4 toons, in fact every item levels a % on the same mob if they are the same level, for me anyway.
Going from 0 to 1 only took 3 kills. On the ring. What concerned me was the sholders not gaining anything until the ring caught up, then past them.
I do agree with shoulders taking longer. I have lvl 4 ring, level 3 boots/gloves and level 2 shoulders. Shoulders were the last item I looted and level 1 went fine but level 2 is dragging compared to how fast the others leveled up at level 2.