For the benefit of those who don't know, Parallel Projection is a flat view with NO perspective.
It's great for straight on plan views - straight at a building or straight down for a top-down view.
Also, in Perspective view you can adjust the 'field of view' and get really exaggerated perspectives, which can be good fun to play with.

Also, with components - you can override the feature of change one-change all by right clicking and selecting 'make unique'.
There are also loads of aawesome free Ruby scripts and add-ons that let you do a lot of cool things.
And because of it's accurate measuring you can use it to create accurate grids of a particular size with subgrids nicely subdivided.