That applies though only if u have more sets of the same value right? Won't replace 69 mod with 63 mod just because it has stat u need, right? Just asking, I don't know what's usual.
For mods, there are lettered versions and non-lettered versions. While the type of stats on a given named mod are all the same (e.g. a Robust mod will always have Will / Endurance / Absorb), the distribution of stats will be different (e.g. more endurance on the lettered versions, more overall non-endurance stats on the non-lettered mod).
Some examples using 27s (DG gear):
Advanced Robust Mod 27: 36 Endurance / 54 Willpower / 44 Absorb
Advanced Robust Mod 27A: 44 Endurance / 72 Willpower / 13 Absorb
Advanced Robust Mod 27B: 56 Endurance / 44 Willpower / 34 Absorb
All have the same stats, yet the non-lettered version has more of the stat budged allocated to non-endurance stats.
And while I don't have the new 29 mod stats handy, I believe in some cases a 29 mod of a lettered version may offer inferior non-endurance stats over a non lettered 27.
Enhancements are similar in that for a given pair of secondary stats, there are at least two enhancements (with different names) containing those stats, yet one will have less endurance, more non-endurance stats.
Advanced Battle Enhancement 27: 29 Endurance / 44 Crit / 60 Surge
Advanced Assault Enhancement 27: 48 Endurance / 24 Crit / 60 Surge
Again both have the same stats, yet the Battle enhancement has more of the stat budget allocated to non-endurance stats.
This also holds true for armoring, barrels and hilts where there are sometime heavy endurance versions (Force Wielder / Patron / Commando / Guardian) in DPS / Heal gear which are actually downgrades from a lower item level non-endurance heavy version.
And this is all before weighing the values of the actual stats, where sometimes the stats on the mods and enhancements of a higher grade item actually are a downgrade as in the case of a lot of tank gear where the mods and enhancement have no mitigation stats and instead have nearly worthless stats such as alacrity.
So really the question that should be asked as you gain 69 or better gear is this, are the mods within the piece an upgrade or not.
And that question cannot be answered by simply saying one is a 69 and the other is a 63, and therefore the 69 must be better.
That question can only be answered by looking at the stat values and determining their weights.
And unfortunately, as my tank is finding out right now, a lot of 69 gear is stuffed with garbage mods that I will not use to replace my optimized 63s.