Thanks for the feedback guys, much appreciated.
Re: The Background.
I do have a couple of backdrops and am probably going to get another couple as well (although the good ones are plenty expensive). It's interesting that I've shown these photos to a number of people, some love the background whilst others are are not so keen on it. Personally I quite like the warm effect it gives but I guess that to some extent it's more down to personal taste.
Re: Shadow.
Yeah, I agree that it would be better to have them stand further away from the backdrop. Unfortunately I have a very, very small space to work in and although I could get them to stand a bit closer to me it would only be about 50cm closer so not sure it would make that big a difference.
Cheers everyone!