Rather the question is can you afford not to use them and the potential speed up of genetic improvement of your herd??
been using genomic tested bulls for the last few years now. And as of yet the proofs have to be established for me in the parlour! That being said it seems to be working on a national level. However there are certain warnings to be aware of.. such as if using these bulls pick a minimum of 5 thus splitting the potential of a bad geno typed bull leaving you with a lot of not so good prodgeny. And of course use no more than 50% of these bulls overall like mentioned all ready use proven bulls too.
As for testing my herd into the future, im certain i will but with the constraints of costs ( v. high individually 77 stg/animal) so it will have to wait ! Plus with the freeing up of the milk market looming i predict any animal with an elder will be milker for the foreseeable future!