I have used the DD 3x3 tarp for 3-4 years now and it has been my only shelter ever since.
Depends on what configuration you will use it, but I have had 4 people under it with no problems.
I have had small cooking fires underneath it most of the times it's been used. By now the tarp smells like a campfire all year round. No problems with sparks so far.
The attachment loops have been holding up very well without any problems. The nylon, however, did rip when it was used on top of the wooden frame. The sharp corners ripped it right open. Nothing too bad, I ordered a repair kit from DD and that has worked like a charm.
Best nylon tarp I have ever used. The next nylon tarp I will buy will be the exact same one.
The brown color also goes well with the spruce trees. I have had hikers go by at 7 meters without noticing me.
As long as you understand the limitations of nylon and take care of it, it will take care of you.