For planes that are genuinly subsonic (i.e. as Shoe say's below about 0.8 mach) then there really arent anyreal advantages. Yes, sweep adds lateral and directional stability but not as efficiently as other methods (like dihedral for lateral stability for instance). And often too much lateral stability is a problem not an advantage. Yes it alters the spanwise lift distribution but it moves lift to the tips which is generally the last thing you want for safe handling or efficiency. It flattens the lift slope due to lower aspect ratio, but that's a bad thing because it increases induced drag.

In the model world the biggest reason for sweep is for scale reasons (on scale models) or in non-scale models because it looks 'cool' or the designer mistakenly thinks it will make his model fly faster.