Having juice with out the fibre is also a sugar hit for your body. With the fibre it makes it a lower GI and reduces the insulin reaction from your body (I have been informed)
My dad is a diabetic and can't have juice from a juicer but can have a TM juice no problems.
People whose health is compromised (like people undergoing chemo) are often advised to have juice from a juicer as the body can access the nutrients quickly with out having to expend the energy to process the fibre. For most people though this wouldn't apply
I am no expert, this is only info that I have been given over time from various in the know people