I sold all my 700's and now I own 2 Browning A-Bolt's... My Stainless Stalker with BOSS is a true .50 MOA gun with factory win grey box ammo... (cheap shtuff)
I have owned many 700s,and only two A-Bolts,one with the BOSS.The 700s were every bit as accurate as the A-bolts with loads that I developed for each.I couldn't tell you how they compare with factory loads,because I don't shoot factory loads.The triggers on the 700s were much better,and only needed to be adjusted with no parts replacement required.
The 700s had a decent magazine system,not the over designed abortion of a system used on the A-Bolt.In fact Browning does not use this silly magazine system on the new X-Bolt.
As far as the BOSS was concerned,it did allow me to optimize the gun for a given load,but the damned thing was extremely loud,and it kept coming loose and changing the point of impact.As well,the BOSS equipped rifles are equipped with barrels that are two inches shorter to compensate for the length of the BOSS,and they produce less velocity than a non BOSS gun as a result.