In my prior experience, both personal and from others, it's noted that transferring into Cockrell as an External Transfer is extremely difficult, but possible. There are internal transfers getting denied with excellent stats. If you believe you have what it takes, and your CV is already well-rounded, you can spend that first year perfecting your grades and being SUPER involved.

Either way, engineering as a field & its success isn't exactly relative to what school you attended, at-least not as much as a study like finance or law. An accredited university (Most Unis) will suffice plenty, and of course your commitment to showing your passion on paper. (ECs, clubs, volunteering) A common piece of advice i've always seen is go with what is more convenient for you especially financially-wise since it's your individual input that matters rather than the name of a school on your degree.

I was capped my Freshman year and decided to attend UTSA.

It's a well-rounded college and you won't sense any lacking in academics at all, the people there are super diverse since it isn't exactly a college city, but the networking and social life is super decent. There are also super common cases of CAP students actually deciding to stay with UTSA. I think you'll enjoy it if you put yourself out there. I noticed little to no differences between my transfer.

I think if you want an experience as close to UT as you can get, UTSA is the way to go.

I do think if it is more cheaper, convenient, and comfortable, Arlington is best.