I think Egypt is a bit undervalued, but come on, better than Brazil ? From what we know Brazil is god-tier, with an insane early adjactancy bonus for several districts, much better GP generation and a unique district.
From what I have seem so far Brazil looks like the science powerhouse, Mabozir was pumping out +50 science in turn ~80 with the +100% adjacency bonus economic card and 2 science districs.
Not only that, rainforest are like already having an improvement in your tiles in the early game with their +1 food over standard terrain. And every start I have seem so far with Brazil gameplay it gets that hugh amount of rainforests near the city.
I think Denkt says it best below:
Brazil may often be without its unique unit, Im not that impressed by its district either and a creative player could cut down its rainforest or just capture its rainforst cities. Rainforst may be a drain to the economy later on because they do reduce appeal, unlike farms they do not give housing and produce much less food then feudalism farms.
It's cool that rain forrest/jungle is more useful than in previous games, but I suspect that I won't want to leave as much of it lying around as is likely to be required to get all the benefits you allude to.
And as much as I love the oceans and anyway to get them into the game more; a late game naval unit isn't nearly as influential as most the other UU's.
I do like Pedro's LA: Magnanimous; but when compared to most other LA's I end up ranking it low.
I think the Street Carnival UI is great, but still only mid table when compared to other UI's.
Egypt get an early unique unit, a significant production boost to both district and wonder, a unique improvement that provide both faith and culture and a significant trade bonus which may be about equal to brazil great people bonus but more flexible.
Damn skippy! Unlike Brazil, Egypt can build over it's (likely) unique starting position; meaning that floodplains are much more flexible than rain forest for their respective Civs.
We do not know the final numbers for unique abilities as such things are subject for change. If they felt Brazil rainforst bonus was to large they may have reduced it. Brazil may often be without its unique unit, Im not that impressed by its district either and a creative player could cut down its rainforest or just capture its rainforst cities. Rainforst may be a drain to the economy later on because they do reduce appeal, unlike farms they do not give housing and produce much less food then feudalism farms.
Yes, this is all subject to change lol. Amen to the rest.
England and France get bonuses we do not know to much about. England get a museum bonus which may be very powerful depending on how it work and France can become a tourism powerhouse very early on. England get the redcoat which may be 70 strength unit in the industrial era, as strong as infantry but a whole era earlier. It can get free units that cost more then the settlers you build to found cities especially if you use the capture and raze strategy. France get an extra spy and that spy come earlier which may be very powerful.
And one level higher diplomatic visibility (France) making it easier to discern both what is happening beyond your vision; and possibly more importantly, what the AI leaders hidden agenda is.
France's UU is a candidate for the best home continent unit in the game, and comes into play at a time where borders are pressing close together everywhere. Having such a strong home unit, allows me to take more of my military further afield knowing the Garde left behind have things in hand if anything goes wrong.
Having + 20% on wonder building for almost half the game is HUGE. And the doubled tourism from wonders for the whole game isn't too bad either
Germany
Depends entirely on the District to Population ratio. No one can know how good their main ability is until we have the game. If we're always bumping up against the Pop cap and thinking "MAN! I wish I could build more districts! Now I have to wait for my Population to slowly climb up!" I think Germany will be a powerhouse. However, if you're never really building all of the possible districts anyways, this ability might be a huge disappointment. Only actually playtime will tell. I'm looking forward to a streamer hopefully playing Germany.
I've thought that with Germany too, but now that we're seeing that you can only have one district per 3 pop, I think this ability is a big deal.
I do NOT see the appeal of Brazil as one of the best. I think the Jungle bonus will be overrated with play experience. Having to keep that many tiles at such relatively low yields will ultimately lead to issues with cities I believe. It's good on paper that you can have a +6 campus surrounded by jungles, but that's 6 of your cities potential tiles. I also think that it'll work out to be less perfect as people are imaging it in their mind.
The Aztecs are the other ones that really interest me. Now that we kind of know more about how luxury resources get divided up, I think they will be quite interesting for big empires.
Yeah, unlocking Brazil's strengths is going to take much more thought than most are seeing I believe. Could be a good challenge for those who want one

With the way amenities look to be working; the Aztecs def have an advantage in building some big cities between their LA and UI.
At the moment I'm thinking the strongest civ is Sumeria; but that's what I thought about Rome when it was announced and Greece right before.
So this very well could change after Arabia & Russia are announced, but I'm currently giving the edge to Sumeria if they start next to a decent size river (7+ tiles long, which is 3 past the city center in both directions)
Reserving one of the river tiles for the city center (so it has immediate fresh water), another for an aqueduct (for that housing bonus), and one more for the Commercial district (bonus to commercial district for river); that is still up to 11 Ziggurats all providing science & cultural bonuses for fast progress thru both the science & civic trees.
You'll need to get a farm in there somewhere

hehe