For every practical argument you make for one option there will be a counter for the other, been there, IMO it's not a decision for tick boxes or lists of pros and cons, assume they are as near as damn it equal in all practical ways, throw the lists away and if you had one of each on the drive, which one would you pick up the keys for to go for a day out in the countryside?
80's are the best 4x4 ever

it's true, 4WD Action said so
Are there lanes you've taken the 120 along that an 80 wouldn't fit? They'll squeeze through some pretty tight gaps. Even a 100 fits most places but are noticeably wider than an 80 in a tight spot.
If you don't buy a knacker I don't see an 80 as needing more looking after than a 120, less if anything and parts will be cheaper. How much for a rear (solid

) ARB for an 80 second hand?
We find the split slide rear windows very useful for access when fully loaded and as ventilation when the dog is on board, sometimes for the dogs benefit and sometimes ours!
The VC in the transfer box is part of what makes an 80 work so well on borderline surfaces where locking the centre diff causes some binding but being completely open causes a loss of traction. In a newer truck with traction control it's less of an issue because that will achieve a similar outcome but it's a very noticeable difference otherwise.