RE: 2 guns to choose from for geese
Personally, I would probably tote the 870 with the hevi.
1. I wouldn't be shooting a fixed full choke for geese.
2. A pump might* be more reliable given the weather conditions. (see your avatar!)
Although, a 23" barrel is kind short. Just don't get too close to your partners or you'll be ringin' thier ears all morning.