Commonly Compared
Ranked in these QuestionsQuestion Ranking
Pros
Pro Many bleeding edge options
Slic3r is often has many cool new features that other slicers don't. For example, it supports a 3d infill with a multilayer honeycomb pattern rather than a repeated layer pattern, which can provide more strength to prints.
It also supports changing the layer height across the model as you like.
Cons
Con No print estimates
No print time, and filament usage estimates.