An early preview version, 0.1, of Pak128.Britain-Ex, the Simutrans-Experimental version of Pak128.Britain, has just been released: download it here (http://forum.simutrans.com/index.php?topic=3040.0).
This pakset so far implements the highest proportion of Simutrans-Experimental features of the Simutrans-Experimental compatible paksets, although it is still incomplete in a number of respects. Nonetheless, it should balance with Simutrans-Experimental better than the standard version of Pak128.Britain. See here (http://forum.simutrans.com/index.php?topic=2710.new#new) for more information about the work being undertaken on that pakset.
Any feedback would be very welcome indeed, especially relating to how well that this pakset is balanced.
A new and improved version (0.2) has now been released. See here (http://forum.simutrans.com/index.php?topic=3131.0) for details and the download link.