Originally Posted by chillinfar

LVL 50 offers chestnut.

It doesn't matter. It also gives you the first 5 Ex-Lvls
I should know, I have half my gals with Ex-Lvls already

They aren't really that useful, except for top50 PvP battles, where having an extra 1 SED in the Top5 cards in game means defeating everybody.
Every Ex Lvl raises the gals SED by 3pts, no matter the rarity.