I don't know if it is better, but I am the lazy sort and feed it whole. It started with researching the different flaxseeds out there for small fiber ruminate animals (which I also have) and the benefits (there are different types of flaxseed.)
I learned whole was just fine and decided I didn’t want the hassle of grinding the seeds everyday or buying expensive pre-ground stuff.
My horse has been on the whole seeds over a year now. I bought him around Christmas a year and a half ago and started feeding them last spring.
It takes a little while and his shed out last year was awful. Coarse, dry, and he didn’t finish shedding until nearly the end of June. It took until July/August to really see the difference and he looked like a brand new penny by then (he’s a buckskin.)
This spring… Wow what a difference! He is already done shedding (with no work on my part) and shines like a new penny already.
While I do feed a hoof supplement, the flax has helped his hooves as well.
Even with the extreme dry conditions that we have seen here, his hooves stay in great shape without cracks or chips.
There have been some really good threads on flaxseed and a quick search can bring up those threads too.