In reply to Big Jim The Climber:
Have you looked at how far £150 will go in terms of upgrading some of your other gear to lighter and more compact versions?
These days I just cannot imagine wanting to have a larger sac, and despite having a fairly good selection of other camping kit I could very easily knock another kilo of two of my overall pack weight by upgrading various items.
PS currently have a Pod Alpine 50+ which is good for 4 day UK solo trips carrying a 2man tent.
Post edited at 18:04