I also purchased a T4 last year and used a few times. As other confirmed already, the tent is big and kinda heavy. Good news is that I can fit it in the back of my 4Runner, putting down a single seat in the back row. It seems to fit just enough to close the hatch (which also helps to keep in place while driving).
So far I only camped in summer. The ventilation could be better. We got windy and rainy nights, no issue with that. Regarding durability, I sadly had a similar issue as
@Edward Ruth. After the first night, I notices that the floor (that since to be made of a sturdier material) had a couple of small holes. I also contacted the customer support that very quickly sent out a new floor. The good thing is that the floor is detachable (hold in place with velcro) so that was an easy fix. The second floor held fine so far after 3/4 additional nights).
The closing process is a bit annoying if you are by yourself but after a few times you can improve and make it faster.
Overall, I am satisfied. Very big and quite tall, very easy and quick to setup. I hope the rest of the tent, especially the structure, will hold fine in the next years. Downsides: it's big and heavy. If I could go back I might buy the T3 instead.