Differences between LayOut 3 and LayOut 2017? Wow! There's a lot of differences. Some of the most noticeable are:
The ability to create tables directly in LO. Import XLS/XLSX spreadsheet files and retain a dynamic link form the original file. Similar to the link with inserted SketchUp files. Auto-text for things like page number, page name. Auto text in labels can display component definition names and/or description. Dimensions linked to the SketchUp file so changes to dimensions in the SketchUp model will be reflected in the dimensions displayed in LO. Smart handling of small dimensions. Arrows outside extension lines, text placed outside the extension lines when the text won't fit between. Automatic leader inserted. In general more stable and a whole lot faster rendering in Vector and Hybrid.There are other things as well. And in SketchUp there are many improvements over SU8.