Greater Gifting crystals include almost all the top rewards that you may want (Except those Tier 5 Class Catalyst). You can get Tier 5 Basic, 6-star shards, 5-star shards, awakening gem, and so on…
I know some of us may not afford to open just a few, but here are a few videos with the crazy opening.
1. COWhale opens 500 Greater Gifting Crystals (GGC)
2. Pep1000 opens 200 GCC
3. Seatin Opens 90 in 3 different Videos
Video 1: 25 GCC Opening
Video 2: 30 GCC Opening
Video 3: Opening 30 again