As you pointed out, the difference between Pokmon EX and Pokmon GX is that the former ones are always Basic whereas the latter ones are always the stage they are supposed to be [1] (except for Tag Team GX cards which are also always Basic)
Thankfully, you actually want Karmic Guide to die a lot, because you really want to put it on the battlefield as many times as you can
New cards and updated effects that slot cleanly into modern strategies
BT17-090 R Tamer Tomonori Ryusenji Color Purple Cost 3 Type Abadin Electronics Card Text 1 [Effect] [Your Turn] When an effect places a Tamer card in one of your Digimon's digivolution cards, by suspending this Tamer, gain 1 memory
Entei ex 91/95 (Rare Holo ex) Suicunes fellow beast shares the top of the set with it, and its another Ryo Ueda piece
They make synchro summoning into level 8 incredibly easy, as well as being available for rank 4 XYZ summons