Mark, I am a rookie when it comes to fruit trees, so take this for what it's worth.

I planted a two year old sour cherry tree this year and I have also been doing a lot of reading to try to educate myself. The articles I've seen seem to say that the 30" height is to facilitate machine harvesting (by shaking) in orchards.

For backyard gardeners, like myself, the recommended height seeks to be between 20" and 24" depending on the article you're reading. This, I gather, is to allow mowing underneath (if you have something to mow there - I just have mulch) and to develop the proper scaffold.

I did not cut my tree back to a whip since it already had some decently developed branches from which to choose. I just thinned out the ones that were too low, selected some properly-spaced well-established low-crotch-angle lower branches for my scaffold and thinned out the rest of the low ones. I then left a number of smaller well placed branches higher up for further development. Once I see which of these are developing the best I will also thin them out to allow for proper spacing between branches along the leader.

I also got some branch spreaders to improve the crotch angles of some of the branches.

I'm sure many people here can give you much more experienced advice, so, again, take this for what it is worth.

Rob