I hope that Monty isn't thinking of bowing out any time soon. He is the main reason I watch GW. I love his calm soothing voice, along with his expertise.
He has just done the Adriatic Gardens series (which was brilliant) which may indicate that he isn't planning on retiring. I know he had a small stroke a good few years ago but he looks pretty healthy to me 
I don't mind Adam and think he would make a good replacement. Carol Klein is very knowledge but her 'laughing' voice really irritates me - sorry
As Calendar Girl, said, sometimes it does seem to be padded out a bit sometimes. I know that community gardens are a good thing but I feel like I have seen them all now 