I have "heard" it on here.
I personally do not own a 7D or have used one enough to have an honest opinion on the features of it. You owned a 7D, so obviously you are going to go take it over the T3i. Its clearly a better camera overall including video and photo. Im not trying to say the T3i is better then it in any way shape or form. Im just saying, for the average filmer, a 7D for sure is not necessary.
What other reasoning do you have that the 7D is worth the extra money? Im sorry, but saying it has a "much better layout" is not worth the $600 for me, nor other amateur videographers. For you? Thats for you to decide. I have heard from many sources that the 7D is not good in low light, actually, worse then other lower end canon. If im wrong, power to you. Im just saying that I have heard it more then once.
I know a ton of people who on a 7D and dont know half of the capabilities of it. Its just not needed for the average filmer and not for someones first DSLR. If they were into photography, I would take it into serious consideration. But for strictly video purposes, doesn't seem like he needs one.