You dont mind chumping or attacking in a suicidal rage, either, since youll receive a card from its death, making it an interesting two-for-one
However, if your cards are still in reasonably good shape, it might be worthwhile to have them graded
This can be one that you had waiting already or one that you just got back from the discard
The first player to start missing land drops in this match-up will usually find themselves at a severe disadvantage, so having more lands/ways to find land makes sense
As for what makes this set in particular special, it adds four more Mega Evolution Pokemon ex, nine Pokemon ex, a handful of illustration/special illustration rare cards, and 18 ultra rare Trainer Pokemon cards
So, from the big-picture perspective of someone who opens box after box after box, the value of the mythics from the set is reasonable