I knew two guys with the "old" a-Bolt slug guns and both shot very well, although I only shot them once each. They had pretty slow twist barrels and might not do really well with the much faster and lighter sabot slugs a lot of folks shoot today.
I had two of the Savage 12 ga. 201F slug guns. Both shot about 2" at 100 yards with slugs they liked but had very heavy triggers. I got a trigger job done on one and it was a lot better. The groups tightened a bit too since the original trigger pull was close to 8 pounds. The Brownings and the Savage 12 ga. guns all kicked like the proverbial Missouri mule.
When Savage came out with the 20 ga. 220 slug gun I bought one of the first ones and it had ejection and failure to fire issues. After repair it has been great. It shoots 3/4-1" groups with Federal 3" tipped Barnes Expanders and has a great trigger (the Accutrigger). I took four shots this season and dropped four deer. Out to about 165 yards it is a center hold and shoot deal with the bullet within 3" above or below the aiming point.
It deserves a hard look. At less than half the MSRP of the Browning it is a heck of a value and it recoils about like my .308 CZ 550-a lot more pleasant to shoot than the 12 ga. guns.
Lance
EDIT: there's a review of the Browning at:
http://randywakeman.com/Review_2011_Browning_%20A-Bolt_Slug_%20Gun.htmand for the Savage at:
http://www.randywakeman.com/Savage220FRifleoftheYear.htmhttp://randywakeman.com/Savage220F.htmhttp://randywakeman.com/MoreWithTheSavage220F.htm