I play in bronze mostly. I tried silver, but I could not get enough chests to make a difference. I find that the extra quantity of chests in bronze is better than the fewer quality chests in silver. The number of cards I receive is good and there's a little sps, very little. But I like the potions very much. Also, if I stay in bronze, I can spend 20 minutes each morning and evening as playtime and I don't drop below 80% Capture rate. Also, staying in bronze allows me to max the end of season chests. Right now I have around 60!