Yes the PowerPoint ui is much better. It takes more space but it's much easier to find features you might not use as frequently.
I haven't done much switching between calc and excel. Formatting issues come up when making or editing a document in libreoffice and opening it in MS office. Especially with impress, the position and sizes of objects will be very different between the two programs. This makes opening a presentation from impress with PowerPoint on a different computer impractical.