I've barely heard "Tamerai Summertime," but I've heard it's a Manaka lead. Risa is my CG oshi, but I think Manaka is the most talented member (besides Momoko), so she deserves it. "Wakatteiru no ni Gomen ne" is a refreshing summer song, and I really like the "Mata mata nankaime yo" parts but the rest doesn't cut it for me. Something about Country Girls leaves a funny taste in my mouth, although I know many people are in love with them.
I think Country Girls is a group that would've shined more if they had an indies period, like originally planned. Since none of them are that skilled yet (except Momoko and possibly Manaka), indies would have given them a chance for trial and error, therefore making them work harder to improve.
I lowkey look at what Country Girls has to offer, but they're not as on my radar as other H!P groups. I'll have to see what else they put out in the future.