EDIT We have had a few more chemsaver diaphagms to change than normal.We've done everything wrong, bigish mix and 100l/ha and not yet washed out properly. I'm hoping it is a bad batch. Ours was ordered some time ago but has only been on farm about 2 weeks. Fingers crossed.
For some choosing a reasonable substitute may depend if there is anything available! Just spoke to my agon he says he know of plenty of sprayers that have not had a problem with this material and another that is "fkd to the cost of 20 grand!" Apparently there is also a variety with a score of 9 for yellow rust that has yellow rust exploding in it....!