Honestly, this game does a great job of making it easy to select gear. An easy way to figure out what's best for you is as follows

1: Check if the gear is for your class. Whether you can equip it or not is the obvious check, but also see if it has stats for you (STR for all DoW besides Archer, Dex for Archer/Bard, Intelligence for DPS casters, Mind for healing casters). If you can need on it in a dungeon, it's quite obviously for your role. Really, the only hard check is tank gear versus DPS gear, but frequently tank gear is GLA/MRD only.

2: Compare item level. Item level determines the stat caps for the item and if it's HQ or a dungeon drop (Or unique quest reward, like the choral gear) it will be at or near the stat caps for the stats that are on it. If it passed test #1, then it will have more of the main required stat for your class. In the case above, you'll notice the choral ringbands are 50, while the aetherial gloves are 45. The choral gloves have the higher dexterity, among other things.

This isn't FFXI where you use the same piece for 50 levels just because it has some accuracy on it. Following these two rules will work in just about every case. The exception is once you start getting way into endgame to the point where you're comparing between endgame pieces of identical item level (Between Allagan and AF+1 for example), or in highly situational cases where you may want to use materia (Apparently the crafted level 70 pieces can outshine even level 90 pieces for certain classes.)z