I think I've cracked it now. I'm pretty happy with how it looks. Added a second bag of AS, it must be about 6" deep in the back right corner! I might mine some out some day and pad it with some sand, cheap skate that I am
Anyhow, I've tweaked the left rock in a smidge, and raised it, along with the back "peak" rock, infact I've rasied them all a tiny amount. I've also added a small accent rock left of the main left rock, which I think works but I'll probably bow to opinion when I'm able to post a picture. I didn't realise but I've left my memory card reader at work, so no pics till monday, unless I use my iPhone camera, which is crappy at best!
You'll just have to take my word for it, it looks a little better now
(I just hope I haven't over tweaked it!)