I recently bought MB Whey Chocolate and am loving the experience. Previously I have used ON 100% Gold Double Rich Chocolate.
Full marks on the taste, the shake was yummy - flavor was stronger than on and had milk undertone. It mixed very well with water. Can’t comment on efficacy, as I have just started using it.
On was a great product but, don’t see a reason to pay so much if I can find a similar substitute at a reasonable price.