The field model ...according to catalog is only 7 lbs 6 oz ...which is pretty light....and the Feather light model is about 13oz lighter...so call it three quarters of a lb...( or really light )...
Just looking at the 2 models in the catalog...weight is the big difference I see..../ price is higher on the Feather model + $ 180 ...and the receiver is aluminum vs steel on the field model ( that's where the weight is ) ../ but I have no reason to believe, if you take care of it, that the alloy receiver won't hold up just fine.
Stock dimensions on both are almost the same....45 3/4" overall, 14 1/4 LOP, 1 5/8" drop at comb ...one model has 2 1/2" drop at heel one is 2 1/4"...( unless catalog info is incorrect ).
For an adult male - 13 oz will mean the lighter gun will give you probably 15% more recoil and that's a lot if you shoot clays with it / in the field where you're only shooting 10 or 12 shells, maybe its no big deal. But is carrying 13 oz a big deal...not to me it isn't / so I would go with the heavier gun.
Personally my field guns...on live birds ...and for Skeet and sporting clays...I like them with 30" barrels and around 8.5 lbs.../ but I don't hunt a lot - and I do shoot clays a lot...so heavier is important to me in terms of limiting recoil.
I have a 7.2 lb gun....if I want really light to carry ...but its a semi-auto / Benelli Super Sport...and the 7.2 lb is the 12ga 30" version / I have it in a 20ga as well in 28" at 6.2 lbs..../ but the semi-auto action - with the comfort tech system in the Benelli stock soaks up some of the recoil...
so on the O/U --- I would go with the heavier gun / I think its more versatile.