I'm not an expert, but I'll share what I think I know.
Each wax has different reflective and optical poperties. Some may give the appreance of a deeper wetter look which would highlight black or dark colors, others may be more relective giving an edge to a color like silver which has less depth, but to make it look very glossy. It just really depends on the look you are going for and like. I find that sealants like klasse and zaino give great shine and suprior protection, but may lack a little depth. Whereas P21s or Souveran give a more rich look, but lack the year long protection of the sealants.