John said it best. We all have slightly different objectives and goals in our gun making. All are legitimate, none is "better" than the other. I find doing everything by hand very satisfying. After inletting about 70 barrels by hand, I have learned to do it quickly and efficiently, this is rewarding to me. Others find that task boring and have someone else do it. There is no problem with that. I bet the masters of the old days assigned that task to an apprentice if they could, which might be the same as sending it off for someone else to do!. I find satisfaction in finding the rifle in the blank and knowing I brought it out, others might wish to recreate a specific gun simply to own and shoot and are happier and more successful with a kit. The end result of both can be a beautiful piece. But your original question is about saving time. With a Chambers, Kibler or other high end kit, I would say yes, you will save time. With some of the mass produced "parts" kits, maybe, maybe not.