Warning :Biased comment ...
(since noone else hascommented)
I just finished adding the liner to my Moment and fitted one for a mate of mine.
mine is 1110 g (seam sealed,liner, 6 pegs, two guylines inc) his is 1330g ,same as m ine plus the extra pole. ( I take spare pegs)
So you are correct that the weight is close enogh, but keep in mind that you need to add the weight of another 2 pegs and a guyline for the SD to vent correctly.
The SD has a bigger vestibule, but the wall slopes inward the Moment outward.
The SD is freestanding but the "American" way, that is the inner (tent in the US) stands up by itself , you need another 4 pegs (that I can see ) to hold the fly down.
That also means if it rains during set up or take down the inner gets wet. Not a big deal for some, it is for others.
The Moment was designed to have a fast set up , stands up with two pegs , another two are required for the reccomended pole guylines .
The extra pole is not really needed most of the time , so in that case you can save about 200g.
You may also find some interesting comments here :
http://www.backpackinglight.com/cgi-bin ... d_id=28811 If the link does not work, it is in the Gear forum (Akto vs Moment) at Backpakinglight.com
Franco