We have backpacked with this tent for several years. There are few tents that can compete on weight in this category (it is weight competitive with many 2 person tents) and at this price point it is a no loss purchase. We also own a Mountain Hardwear Hammerhead 3 tent but even when winter backpacking in NC & VA we carry the Sirius 3 (4lb lighter) unless we are expecting large amounts of rain or snow.
One note: since the weight savings comes by going to a 2/3 size fly it is very very important you consider wind direction when setting the tent up (yes, we learned they hard way on a late spring trip in the mountains of Virginia when the temps dropped below freezing, winds hit 30mpg and the rain fly channeled the wind onto our 32deg bags; if we had set it up with the fly to the wind it wouldn't have been so cold!)