I have no personal experience but I looked into this a bit when deciding if I wanted to go with a new dryer/diffuser or a bonnet. My thought is that, yes, the soft one should give you more mobility. To walk around with it might not be especially convenient but to stand/sit and do makeup or sit and watch tv, check emails, etc it should be good. Even one that connects to your dryer could probably run while you do you makeup - you would just have to prop your dryer in a way that provides airflow to the dryer but holds it in place. I think a hard one would severely limit any real movement and would not allow you to sit under it in a way that you could apply makeup or do much of anything productive.

I opted to go with a diffuser/dryer set-up simply because I wanted more control in forming the curls, and I don't work outside the home so I usually don't have the time issue.

Again, those are just thoughts to help you think through what might work. Hopefully someone with first-hand experience will chime in with more thoughts, too.
remember, with all advice or suggestions for your hair, YMMV!!
My hair:
2b wavy, medium texture, low porosity, med-high density. Protein finicky.
My routine:
Cleansing: DCNP, every 4-5 days (occasionally use CJ cleansers).
RO: CJSC, occasionally use JCDC
LI: KCKT or CJSL
Gel: KCCC, CJCIAB for 2nd day hair (sometimes third)

Heat is my friend: warm water rinses, steam caps, and diffuse dry. I love CLU cloths and my Denman.