I have all three right now (Manners, McMillan & HS Precision). If you are looking at upgrading for better accuracy, then you will probably be disappointed. The HS is a great stock with great accuracy potential (assuming alum. bedding block). Any small increase in accuracy/grouping will probably not be worth the incremental cost.
If you are looking to upgrade based on fit or style, then you will be very pleased - and the addl. cost will probably be worth it.
I had no problems with my Manners Ultralight Hunter. Inletting was perfect, with only a light skim bed added. Having said that, my Manners was purchased some five years ago. I cannot speak to their quality control at this time. Customer service was exceptional for me.