Many thanks for all your replies, I do love this forum.
Ok so far we have: High speed
Stability (or disadvantage)
Dispensing with the tail
In terms of modern Pax/cargo jets, If asked, "what are the advantages of wing sweep besides the higher Mcrit?" I would still be stuck for an answer.
I always thought that wing sweep created the Dutch Roll problem (obvious disadvantage) And I cannot see boeing/airbus chopping off the tail any time soon.
Thanks again guys and girls
N