"Another reason is you have more adjustment for mounting your scope if you use a picatinny style rail in order to get perfect eye relief."

Exactly. The long action Savage is pretty long and a lot of scopes' tubes can be pretty short and sometimes hard to get mounted with the correct eye relief. The one piece picatinny rail takes care of that. You have many places you can put the rings which allow for more movement of the scope. Also in my case, I needed more clearance for the objective over the barrel. Most of the picatinny rails are thicker than two piece bases thus giving you more clearance over your barrel. I could have gotten taller rings but I wanted to stick with my Signature Zee rings and I had the tallest ones they make for the 1" tubes. So the one piece base gave me more clearance. It is a little more difficult to load through the ejection port on the action but it's not impossible. I do it all the time. It also doesn't interfere with ejection. My empties shoot straight out the side and clear the rails.