Buckshooter, I used a pair of 212F 12 gauge slug rifles for years. They both had very heavy triggers so I had a trigger job done on one. My son and I were quite happy with them. Shooting 1 ounce Remington copper solids they shot 1-1/2 to 2" three shot groups with none of the uncalled flyers common in some slug guns. That was about as good as it got in those days. The new 212s have the Accutrigger and, from what I hear, shoot tighter.
When the 220 came along I bought one of the first ones made. It is 3/4 of a pound lighter, kicks a lot less and has the Accutrigger so I felt it was a big step up.
Mine, like other early ones, had erratic misfire issues due to soft firing pin strikes. It got sent back to Savage who, after two tries, got it fixed. To their credit they called me each time to discuss the issue, shot over 50 shells through it the second time to be sure it was right etc. It has been 100% reliable since then. There are a bunch of 220s around here and I'm not hearing any misfire issues anymore. Fortunately, I had gotten mine just after deer/bear season so the delays in it going back and forth were not show stoppers especially as I still had the 212s. I'd have been through the roof if the 220 was my only slug gun and the season was on.
Mine prefers the Federal/Barnes 5/8 ounce tipped Expanders and plunks them into 1" groups with monotony as long as I keep the loose nut behind the recoil pad tightened up. Federal recently dropped that load and replaced it with a similar slug that has a lower ballistic coefficient so I ordered 3 boxes to see how the rifle likes them. The new load is about $4 a box cheaper so I suspect Federal is making the new bullet. I sure hope it expands and kills as efficiently as the Barnes bullet.
Over the years I have been mildly surprised that any ammo maker can produce slugs that work well in a variety of guns. There are no industry standards on barrel dimensions, rifling twist rates etc. Your Savage will come with a hang tag listing the recommended slugs that tend to work well with the specs the gun is made to. Try those first. If one of them works for you, great.
If one doesn't work well it is important to try every similar slug you can get your hands on until you find what your rifle likes. Don't be limited to what the local gun shop sells. Your gun is an individual and it will decide which slug it likes. My experience has been that more shooters who claim to have accuracy issues with any slug gun really have ammo selection issues. Many of the folks I have heard complain about 220 accuracy are using whatever the local shop had for sale and have not put the time in to find the best slug for their gun.
As an example, my gunsmith has a 220 (his son too) and his and mine like very different slugs. His like 3" Remington Accu-tips which mine won't shoot worth a darn and his won't shoot the Federals mine likes. I've seen the same thing with other makers of guns too.
EGW makes a scope base rib that I highly recommend. The length of the ejection port means that with standard bases you'll need a scope that has a long reach between the bells and you will not have much room, if any, for fore and aft eye relief adjustment. The rib allows you to mount any scope you want anywhere you want and still leaves ample room to single load directly into the chamber.
I know all this is a little long winded but I hope it helps.
Good luck and please check back to let us know what you decide.
Lance