I don't dive an Express Tech, instead a Zena, but I can say that I do strongly recommend anything Zeagle. However, what I would also strongly recommend is that your girlfriend TRY any BC she is considering before she buys. Fit and comfort is the most important thing and varies greatly person to person.
As an example, I find bare nylon straps to be uncomfortable as they tend to cut into my body so I prefer something a bit padded and more finished on the edges. The funny thing is that the bare nylon straps didn't bother me until I had a tank on, making them pull and cut...both in and out of the water. Other people obviously don't have the same problem.
My best advice is always TRY before you buy and never buy simply off of anyone's recommendations. That's a good place to start looking and trying, but we're all a bit different, so trying things on and if you can, in water, is your best insurance.