Sage TXL is the benchmark for ultralite fly fishing.  From a rediculus 000 weight up to a 4weight.  This is the spring creek specialist when delicacy and accuracy matter on those long glides. 

You are thinking "yea right, maybe for the UK or North America." , but think about a 5 pounder on the 4 weight.  I have heard from accutual customers that it is so fun it should be illegal.