Choosing between several phrases that seek to highlight a positive aspect [closed]

I would like to know the common usage/difference/when is it appropriate to use these phrases:

• I have been exposed to the [some positive aspect of a thing]
• I have first hand experience with [some positive aspect of a thing]
• I have seen first hand the [some positive aspect of a thing]
• I am more than an acquaintance with the [some positive aspect of a thing]

I'm writing a motivation letter for grad school at the same university I'm currently in, and would like to highlight a particular thing I like from this university.

All of your choices of phrase indicate some level of familiarity with the positive quality you're describing, but there's subtle variation in exactly how familiar you are with the positive aspect, how frequently you experienced it, or how active of a participant you were.

• I have been exposed [...]

In my view, the word exposure typically indicates the first experiences you have with the quality you're describing, and both the word exposed and the passive voice tend to make it sound as if you were more of an observer than an active participant. This stems from the "make known" or "disclose" definitions of expose Merriam-Webster

• I have firsthand experience with [...]

This phrase indicates that you were an active participant in the activity or quality you're seeking to describe. It doesn't necessarily indicate that it was the first time you've experienced that activity, just that you played an active role in it.

• I have seen first hand [...]

Like the preceding, this phrase also means that you were present for the activity or quality, but the word seen and passive voice give the feeling that you were more of an observer than an active participant.

• I am more than an acquaintance with [...]

This phrase stresses your familiarity with the activity or quality -- you're no mere casual observer. It leaves ambiguous whether you were an active or passive participant, but (unlike the first option) doesn't indicate that this is a new quality or activity for you.

Other options you might want to consider:

• I am well-acquainted with [...]

Like your last option, but less clunky.

• I first experienced [...]

If the first example's focus on novelty is appropriate.