However the day which I had chance to do this was very overcast which you can see from the images. I believe that using fill in flash would be more beneficial on a sunny day when shows are being cast on the subject. The flash would then highlight these darker areas.
The images shown below and in the link provided still demonstrate the effect of Fill in flash and give me an idea of what to expect when using the flash in the day.
I did notice difficulties when using the flash in daylight. One of which is that the camera kit I own is reduced to a shutter speed of 1/200 with the flash in use.
Due to the fast pace of snow sports I found it more difficult to time my shot. Whereas without the flash in operation I am able to take 4 shots of the subject before they land from a jump.
The timing of the shots is easy to overcome after a few trial shots. The biggest downfall of this technique is that I cant be as close to the subject as I would like without the image blurring to some degree. Shown below.
From the review of the shoots in Austria and Aviemore it is clear that the better shots are those taken within close proximity of the subject. Either at the side of them or even underneath them as they jump over me.
You can still see from this image that the flash is having some effect and is lighting up area which would normally be in shadow. For example the ruffles on the trousers and under the eyes.
The rest of the images from this shoot can be seen in the slide show labelled Fill In Flash Trial 1.