After reviewing the options available we have decided to concentrate on the "commisioned" sounds specifically blow into the decoder to our order by Bryan Robertson. These sounds are sharp and a little stronger than the ESU sound range. This is purely a personal preference and in no way detracts from the sounds available as an off the shelf product.
On this basis we will be offering sounds to cover our smaller locos
Terrier & J50 only we do not recommend this decoder for anything larger.