LDON raids have tank AC augs that are BIS for a very long time. Also, +% spell mod augs like +10% Evocation etc that are good well past their expiration dates. I think the AC augs might last the longest though. They don't get replaced until like...some point much later, IIRC. I don't know because I never played a tank past PoP. Type 3 aug slots start getting use again in SoF+ which means a lot of LDON's better augs go back to being super-useful in that timeframe. There's also the +8% dodge type 3 aug that ends up being super-useful for a long time.
Another thing LDON has, but with group currency rather than raid, is the Black Diamond of Crippling. Damage aug for Type 5 slots (LDON weapons). Thing is, Type 5 slots make a comeback later on in the game. Expansions at level 105 onward have Type 5 slots in all the weapons, so the BDC makes a big comeback as a free extra damage aug on top of your other damage augs. Every Zerker/Monk should have one of these slotted into their two-hander for like the last six expansions of the game.
