Like what will he be like when he comes back? im thinking about it like this. on the Juki LT scale of 1-10. 1 being low. 5 being the average LT and 10 being the kind of LT that Juki wants. the training would slide Gio from his 2. to about a 6 or 7. 

Skill wise, the concentration is still Kido. hopefully he can walk away deserving of the vice Kido chief title. 

the biggest thing bout gio is that his shikai makes kido much easier. which is why lately he's been trying to do it without. So if he reaches the above level without shikai. imagine what he will be capable of when he activates it?

but he wont be getting his bankai or anything that ridiculous.