What is the difference between BTD and Q35 What is the difference between BTD and Q35 What is the difference between BTD and Q35 What is the difference between BTD and Q35 What is the difference between BTD and Q35 What is the difference between BTD and Q35 What is the difference between BTD and Q35 What is the difference between BTD and Q35 What is the difference between BTD and Q35 What is the difference between BTD and Q35 What is the difference between BTD and Q35 What is the difference between BTD and Q35