Alexis at times had no redeeming qualities. The thing that stand out the most is when she caused Krytle Carrington her child. But she did have deep love for a few people including her children and Dexc Dexter.
Stable's min down-fall was to direct all her anger at Jeff Colby. What Constance left Jeff was non of her business but she schemed and plotted until it cost her her marriage and damaged relationships with her children.
On the other hand Stable was very vunerable and loved deeply to the point of sacrifing herself for others.