RE: 3 1/2 vs. 3"
I am of the opposite I would tell you buy the 3" you really do not need the 3 1/2 if you want to have a 12 guage that shoots like a 10 guage buy the 10 guage. You will be a LOT happier.
In honesty the 10 guage with 3" shells will kick you less than the 12 with 3 1/2.
Next I would recomoned that you use the extra money to buy a case of hevi shot when you can find it on sale. That with a 3" is all you will need to use for geese. I prefer 2 3/4 shells and I use Kent for speed. I have found that speed is a lot better then more bb's it will put you with a better chance to take the head shot.
Well that is just my .02 cents worth though. Everyone has a different opinnion and that is why there is so much stuff out for waterfowling Aholics. We are never happy until we own or have tried them all.