We bought the Titan because of the size. It fits two cots plus luggage in 1/2 of the tent. The other 1/2 fits two blow up twin mattresses. This half also has an asile and fits our luggage nicely. You can stand and walk around in the tent. Checking on the kids at night is a breeze. The side with the two air mattresses could fit another twin air mattress. But then you couldn't walk as easily.
We had rain the first night and we stayed dry. We moved camp sites and put our tarp down at our new location and it was still wet. We put the tent up anyway. The water never came threw the bottom. When we took the tent down 3 days later the water was still on our tarp but not in the tent. We also bought the Eureka Northern Breeze screen house. Expensive but worth it!