.... (quote the whole line not just a few words) I still say use them to fill in cards until you stop getting a lot of "new" cards... after that it's your choice on how to use R-gatcha's.
Okay... Well in regards to the R-cards.... They are the most frustrating of the 3 tiers. Usually you will see new cards added to that pool when they do limited cards (you will see what's available to the right during gatcha) but those are hard to get. There are 2 ways to think of them...as sed builders or headaches. I go with headaches because that's what they have given me. When you feed a single R-gatcha to Kirito most times you will get a SR-wild and an R-wild, that's how I have been leveling up my R-cards. Like I said, after a bit you will get the hang of it and know what works best for you.
Now about EX-wild and guaranteed SR. Save your EX-wilds until you reach level 50. that's when your level 100 cards gain "EX levels" (don't use them on N-cards though). The guaranteed SR-gatcha is a joke. All it does is guarantee 1(one) of the 6 cards will be an SR. I has hoped when I first saw one it would be like the R-gatcha, 6 SR-cards. ... that's all for now. Update a lot later... SR guaranteed gatcha has a separate list of cards not available to R or N gatcha rolls. (I still think you should get 6 SR to choose from...)