As it happens I have! Yesterday morning I managed to find a Marsh Warbler at an undisclosed location in the Broads.
I picked the bird up singing from a very dense bit of vegetation but it was extremely difficult to see, I managed a couple of fleeting glimpses, enough to see that it was an acro and it was also evident that it was quite a pale hue, unlike the warm brown of a Reed Warbler. The birds' song however was the real clincher and like most Marsh Warblers it went through a good repertoire of mimicry as can be heard from the video below, its best from 30secs in and the bird itself does not feature in the clip.
Last year I failed to find anything to really shout about however this May I have managed to self find RR swallow, Savi's and Marsh Warbler (290)....still no Icky but a fair compensation!
Enough of a buzz to give a good old fist pump, the double of which is well demonstrated by this Cockchafer!