The perfect bluetit box

 They were on holiday last week and I thought to my self perfect opportunity to get rid!  But I wouldn't sleep at night.
I agree with all you said  and next year we may have nests in the very boxes that were not chosen this year, my main change is ensuring they have variety of types and hole sizes. the positions wont be different as I dont have a lot of options available but the GTs I hope will try again next year as they will fit in the new tree box I have for them.   
I learn from these birds every year, each female have their own way of doing things. It is wonderful to be able to observe them, I look forward to welcoming the fledglings