I don't value E+ at all, so I don't factor that into the decision. I almost exclusively do international travel, so lounges and elite access on the *A is a big thing for me.
Based on the responses so far though, it looks like I would be giving up a lot more to become *G than what I would be keeping if I stayed UAS.
If you do mostly Intl then hitting the min Spend of $5k should be doable, or $25k on a Chase UA CC wipes out the min Spend requirement. If are UA G that = *G as well = entrance to the Clubs when you are flying on an Intl tkt even in Y. The only sort of advantage an AE *G will give you is entrance to the lounges even when youre on a domestic tkt, but if your home airport doesnt have a Club and you usaully have tight connections you wont get much use out it then any how.
theres no right or wrong choice instead each person has to know what they need and see if UAG or *G gives it to them