Landlords won't generally let you make structural/material changes to a floorplan without a longterm lease to justify it. However, you can make some pretty snazzy temporary office space that doesn't require permanent modifications to the space using privacy walls and glass partitions[1].
From a structural standpoint, they're basically fancy cubicles, and made by the same companies as standard cubicles. The most damaging thing they do to the structure is mount the tracks for the glass into the floor and ceiling. But that's usually considered normal wear and tear since it's easily fixable on move-out.
From an aesthetics perspective, they're effectively mini offices and can be done very well, making a space look nice and chic and making employees a lot happier. All with what amounts to some fancy cubicles.
What do they actually do for noise mitigation though? If people can't take calls in them without disrupting others, and if someone could theoretically still shout at their neighbor when they need to have a discussion it sounds less than ideal.
Depends entirely on the type you get and how you install them. If you get floor to ceiling types with appropriate glass, it provides just as much sound isolating properties as a traditional office.
And with appropriate sound dampeners (either on the ceiling, as artwork or whatever on the walls, or a non-glass side), you keep the sound within one from echoing or sounding hollow. A few setups I've seen involved using opaque glass as a side/separator between alcoves, and hanging sound dampeners disguised as artwork on those walls. Another used faux-walls made out of the same material as traditional cubicles to separate each micro-office, and that material is designed expressly for sound dampening. And works really well if it's floor to ceiling.
From a structural standpoint, they're basically fancy cubicles, and made by the same companies as standard cubicles. The most damaging thing they do to the structure is mount the tracks for the glass into the floor and ceiling. But that's usually considered normal wear and tear since it's easily fixable on move-out.
From an aesthetics perspective, they're effectively mini offices and can be done very well, making a space look nice and chic and making employees a lot happier. All with what amounts to some fancy cubicles.
[1]http://spaceplus.com/products/glass-office-partitions/