To be honest I'm of 2 minds when it comes to the draft and maybe that's because I was in when they made the change. I volunteered during the draft.
Looking back most guys that had been drafted were usually tougher mentally in my experience, maybe it was because they didn't want to be there. There were few that filled up the hooch with the sweet wiff of the poppy that were drafted but for the most part you could dig a hole and let the chips fall where they may.
The guys volunteering, again in my experience and during that time, were mentally and physically much more prepared for the military than the typical draftee but most joined for the benefits and never believed after Nam they would ever actually encounter a combat situation given the tenor of the country.
I think on the whole an all volunteer force has been a success. However, unless we are going to open up the services to immigrants there are simply not enough young people to fill the need.
However onerous the draft needs to be reinstated in my opinion....