Premium economy on SU?
 

Looks like i can book A class premium economy on LAX-SVO for about $100-150 extra each way. Seems like a reasonable deal given extra miles (about 3K difference each way on DL) good meals and obviously some extra space.
Any pros/cons there?

I'm not a fan of SU premium eco. Yes, you get more food than in economy. Yes, there's more space than in the average economy seat – but that's it.
On the other hand, the seat doesn't recline but slides forward. This strongly reduces actual leg room. You also can't comfortably turn in your seat. On my last flight booked in A, I voluntarily downgraded myself back to eco (row 17) in order to get my legs up.
Also, Aeroflot is inconsistent with their miles. Last year they sold A as a premium fare (200% miles), however I only was credited 150% on the actual miles flown. Only 1 announcement in Russian had been made on their news site.
If I had the choice between Aeroflot 77W Eco and Comfort (premium eco), I'd go for Eco, then select row 17 (all) or 18 (seats C or H) => Expedia allows you to see seating availability BEFORE booking the flight. Aeroflot's "value" fare class (M, U, K, H, L) also gets you 150% miles.

Thanks for your input about Aeroflot seating. Maybe you can clarify something for me. I am also torn between eco and row 18. I am traveling with my young daughter, so I am not thrilled about eco since it has unmovable armrests. But I am also not sure about row 18. According to seatguru, 18H has a tray in the unmovable arm rest. I winder whether you know / remember whether the armrest is on the aisle side or the other side.

You have to be in Economy Comfort in a "W" fare instead of the "S or A" fares. When you book there are two levels with the "W" being higher cost but awards 200% vs 150% miles in "S or A"

Yes, you're absolutely right for tickets booked today: S and A fares aren't "premium" and only 150% of award miles should be credited. However, if today I bought an Aeroflot ticket in S or A fares, I wouldn't bank on getting 150% miles. That's due to my experience with the particular ticket I referred to. It was booked in June 2015 when all Comfort classes (A, S, W) were "premium". Flights took place in December 2015.

The screen shot is a December 2015 version of https://www.aeroflot.ru/cms/en/flight/fares_description . If I understand the highlighted sentence correctly, "Premium-Comfort fare group" rules and conditions should be applicable to tickets bought in June 2015 in "A". The page has been updated in 2016 to legitimise the retroactive change of fare rules and conditions.

i just flew in Comfort from LAX to SVO. Overall, pretty decent, though not as much leg room as I'd want on a 12 hour flight.

Interesting thing - if you have SU miles, you can upgrade from Comfort to Business for 17k at check in.

ime on same route business was full, economy near full but e+ was half empty both ways... hard to take advantage of extra dpace with shell seats but still feels less crowded...

First upgrade at Check-in experience (comfort to business)
 

Just tried my first upgrade at check-in / transit with Aeroflot.
Arriving from AGP in SVO I went straight to the transfer/check-in desk before passport control in terminal F. The lady first told me that upgrades from booking classes A, S, W are not permitted. After a few phone calls she finally admitted that it is possible. 30 minutes later she told me that I was waitlisted for the upgrade and the cost would be 15000 miles.

At the gate I was given my new boarding pass for class "J". Service was outstanding.

Two weeks later I open my Aeroflot bonus account and notice that 30000 miles have been deducted.