I finally killed my original fixx motor for good recently. I did not want to spend alot to continue flying this plane, and I had been somewhat disappointed in the performance. I ordered the S2 twin IPS motor and two heat sinks. (the heat sink really should be standard on the original motor)

I ordered this from Balsa Products http://www.balsapr.com/
7.2V <b>Twin</b> S2 Power System (IPSD-RXC-2S) Price: $21.88 Quantity: 1 Total: $21.88 GWS Heat Sink IPS-8A (EHS-50) Price: $1.45 Quantity: 2 Total: $2.90
Sub-Total: $24.78

I am using the original 9.6v 270mah battery, original 8x4.3 prop and the original speed controller so, not a huge investment. I had to break the motor mount stick out of the airframe and turn it on it's side. I epoxied this back into the airframe. I added 1/2 oz of lead to the nose and cut away the foam at the tail around the motors to give plenty of cooling. I test flew it in a 20mph wind this weekend and WOW! It flew awesome. I would not even fly the stock system in a 5mph wind previously. The added weight helps with penetration of the wind, and the flight characteristics were amazing. I did not notice much of a drop in duration, although I wasn't checking for this. I would recommend this as a cheap, easy upgrade for the fixx even if you haven't melted down the original single motor yet.