In October we had it on the beach at Cape Lookout. High winds all night long. Used the tie-outs and didn't have a problem. In fact, set up right next to the tent was their gazebo as well. Also staked down and tied out and no problems.The big T4 with the "sun room" or whatever it is, is on the future purchase list for me. If it's just me my little Kelty 3 person works fine. But when I take the family places me, wife, 2 kids, however many dogs my wife can sneak into the Jeep. You quickly run out of room.
How does everyone like these big boxy gazelle tents in high wind conditions? I've held off on larger tents for years for this reason. I've camped in some pretty hellacious wind conditions and don't want the tent collapsing in on me.
That being said, if you do not tie it out and a gust collapses one of the hub points on a side wall, you don't want to be on the inside as they come in under tension and could easily hurt a young one.