As an addition to my last post I decided to leave the tent pitched on the back lawn for the last few days to see how it coped with some crappy weather. Over the last few days it has rained quite a lot including this morning which was massive downpour that flooded most of my back verandah and rear yard. After the rain stopped I went and got into the tent and was quite happy to find that there was not a drop of water on the inner and all the walls and inner roof were dry. I have pulled it down now and found the bottom of the floor was soaked on the underside but again was totally dry inside so overall quite happy. I'm pretty happy now that at least I know it will keep me dry if required.
As far as the Scarp vs Helium goes there are several thoughts I have on them both.
The Helium in reality is not a true 2 person tent unless you like being very squished. I bought it as a 1 person tent and would not try and put 2 in it unless an emergency. I would say it's more a fair comparison to the scarp 1 not the scarp 2 as the scarp 2 is definitely more of a true 2 person tent.
The helium has only 1 entry (my older model) and one external storage area where as the scarp has 2 entries and 2 storage areas. The helium isn't straight sides on the inner but pushes out on the side opposite the door so you can store gear (pack etc) inside standing up but some would prefer to have the external storage instead (personal preference really I think.) I think the newer model has 2 side openings but not sure if entry is possible from both sides or not....That would imrove the design again I think.
Overall I think the Scarp is a good tent in the fact that you can buy 2 inners & crossing poles so effectively you can use it in warmer weather with the mesh inner and both doors being able to be opened and also the solid inner / crossing poles for cold/crappy weather. I think if I had to choose 1 tent I would probably chose the scarp for that reason alone as its a bit more versatile.
Seeing's as I don't have to choose though I'm going to get a Scarp at some point and then have both

! Hopefully one will come up for sale in Aus at some point when I have some spare cash.
I wouldn't mind actually looking at one in person though so will have to try and find one in Adelaide that I can have a gander at!