AS% even after beigmore than 2 years old - is still a strong performer. If i had to choose between teh two TIM's I'd go with the AS5 route, however i reserve my TIM choices to MX-2/4, Prolimatech PK-1, Shinetsu + ICD24.
The cooler master stock thermal paste is a great performer. Though, it does not perform as well as the antec-7 but performs roughly 1-2C hotter. Refer to it as cooler master compound or stock cooler master compound.