it's not about speed, it's about the result. I have been reborning for some 8 years and it still takes me a long time. It takes me weeks; i cannot do more than about an hour at one time, so it is difficult to add the actual hours. Also some vinyl, and even just some spots on on head, are more difficult than others. The longest I took to root a doll was more than year LOL; I took lots of breaks.......... Just concentrate on how it looks, not on haw fast you managed to do it.
Years ago, there was a video on utube of a woman rooting doll by stabbing at it at absolutely furious speed and she rooted the head at no time at all. It looked absolutely hideous; sticking in every direction, huge plugs and tails everywhere. Wish I could find the video, it was quite funny to watch.