Why?
They're deeper than the Ready Tactical holders and hold the speedloader with a bit more pressure both of which help a great deal when using "Bubberized" speedloaders in particular. This is not to say, of course, that the Ready Tactical holders won't work.
You might also try Master-Tac. They are a new company but have good quality products. Check them out on facebook or email them at mastertac1@gmail.com. Just tell him what you want and he can make it for you.