Functioning labels are very disrespectful to autistic people and I don't like them at all.
Since I have been referred to as "high-functioning" for most of my life, though, I will occasionally use them out of habit.
However, high-functioning is not the same as mild; people have told me that I have "mildly affected by autism" without knowing the areas I struggle in. And if you're labeled as "low functioning," people don't know about the areas you succeed in.
For example, I struggle with organization. My handwriting is very messy, though it is getting better, I don't plan ahead, I procrastinate, and I lose things a lot of the time.
Also, I'm not the best at socializing. When I was younger, I usually talked about myself/my special interests most of the time, and I preferred to play alone. I'm more social now, but I'm still considered "awkward" and "not normal" because I don't make eye contact and sometimes flap my hands if I get excited.
I'm not completely sure about what sensory stimuli bother me (if I was sure about that, and about what types of fidget toys I need, that would be great) but I do know that I don't like shirt collars to be too tight around my neck, clothing tags will occasionally irritate my skin, (depends on how big the tag is) I don't like loud and crowded places, hugs, people touching me unexpectedly, or the sound of whistling. I hate whistling, especially when people do that weird thing where they whistle and hum a note at the same time. My ears hurt just thinking about it..