I would explore what's best for your gaming experience. If you are in the game to win at arena or conquer certain elements of the game like haat then move to a stronger guild. But if you are in it to make friends online and like your guild then stay with them.
I had the exact same thing. But I chose to conquer the game. My arena started slipping to 40th and the game felt stale. I moved and am loving it. Arena already back into top 10. Only cause I can focus on playing. But then again I didn't have time to enjoy friends in the game only play the game so
