I quite like the Ponsford stand, but I am in a similar boat to you in having 3121 and have upgraded to Inner Circle but not sure what I will do for next year.My first year as a 3121 member and I reckon it's the biggest rip-off ever. $1025 ($1060 if you didn't get in early) and you have to find your own seat. it's Ok if you're on the piss and staying inside, but I haven't been drinking for a while.
I will be downgrading to premiership circle next year. Just as good a view half the price and you have your own seat.
The only good thing about 3121 having no reserved seats is that you can take guests and sit together (if you get there early enough to find a good seat). The AFL members section for away games at the G is good, too. not sure what our entitlements are for this week though.
I also notice the past two games (since the upgrades) that the atmosphere has been, let's say, a bit more raucous up in 3121, probably with the influx of reserved seat holders getting their free upgrade to 3121.
I upgraded to Inner Sanctum for free, but haven't been over there as I don't like the Ponsford Stand.
I don't really take advantage of all the extra perks and the main thing I want is just to be able to turn up to every game and get 2 guaranteed grand final tickets if we play, so a downgrade is probably my best option. The 2 x 3121 or 1 x Inner Circle is a lot of money each year to not take advantage of all the extras.