User Review: Sierra Designs Sirius 3
Ease of Setup: easy
Price Paid: $160 with footprint
Wow, amazing you can get this tent for 100 bucks now. Anyway, other reviews summed up this tent really well, so I feel there's not a lot to cover.
It wouldn't be great in extremely wet conditions if you had to traverse in and out, but waiting out a heavy rain for the night with no pee breaks was fine. Have used it numerous times for 3 season backpacking. Setup is quick and easy. Vented well with minimal condensation. Enough loops and pockets to keep 2 people satisfied.
Weaknesses are definitely the half fly with lack of fastpack and the weak "boot vestibule" which barely even keeps the boots dry. I've car camped with 3 guys just fine keeping most everything in a car, but 3 guys with backpacks full of gear? Think twice about that.
Know what this tent can do: 3 season backpacking or light camping in good to fair weather conditions with 2 people. 3 people if you aren't picky about getting you/your stuff wet.
And what it can't do: 4 season backpacking and 3 person backpacking in extreme conditions.
If you take these into account and use the tent for its intended means, you will be happy. Which I was.