Because the Planet T5/R6, my favourite (i.e. cheapest) 2.4 GHz radio gear has been discontinued, I have been looking for an alternative to use in the garden. A posting on a live-steam group led me to DelTang who produce kits which are also available assembled from resellers http://www.deltang.co.uk/index.htm I have seen a number of 16mm and G drivers using them, and plan to try the system as soon as the Welsh/Brazilian (its a long story) locomotive that I need it for is running.
What I hadn't considered was their use in the smaller scales. The handsets are much smaller than conventional RC controllers, whilst the smallest receiver (costing EUR36 with an on-board ESC) is less than 10mm square. There is a photo on their site of a larger receiver (11 x 22.5 ) and LiPo battery in a two-axle N gauge loco. Imagine no more track cleaning - ever!