If warmth is your only concern, then the micro-puff is your ticket.
However, the MontBell scored higher in the useability dept according to BPL. Its more useable because it can be worn in a broader range of conditions, especially when combined with other layers.
Also, according to BPL, the Thermawrap insulation is 1.8oz/yd where as the Micropuff is 2.6oz/yd.
In the 1.8oz/yd group, it blew away its primaloft competetion in the areas of Loft to Weight Performance, value, and "average score" (except for the MEC which threw the curve with its $60 price point)
Edit: didnt see that the original post was compairing the Montbell PARKA.
If your compairing the Micropuff Jacket, with the MontBell parka (both hooded with equal loft) Id give the nod to the MontBell. Given its performance of the lighter jacket in the BPL review, and given that it weighs almost 8 oz lighter than the MicroPuff jacket. The MontBell also costs less.