Personally, I like having more than one build for each character, so I can change them according to what I need or to have some fun with it.
The problem is that whenever I want to change my build, I have to visit a city to refund my traits, which gets a little boring and frustrating.
So, I was thinking that manuals would solve this problem.
Instead of asking the trainer to refund your traits, you would instead buy a single use manual and use it whenever you need it.