Provided are thermoplastic elastomer compositions, many dynamically vulcanized, with superior crystallization kinetics, methods for making the compositions and articles made therefrom. The thermoplastic elastomer compositions comprise at least a propylene polymer thermoplastic, a rubber and a crystallization additive. The processes for preparation of the thermoplastic elastomer compositions comprises dynamic vulcanization of mixture of a propylene polymer thermoplastic, a rubber and a cure agent followed by addition of a crystallization additive. Further, preparation of articles from the thermoplastic elastomer compositions may be accomplished through traditional thermoforming operations useful with conventional thermoplastics.