David has posted an article on the GP 10.0 Individual Windows Design. He has also listed 4 points which reasons this complete changeover.
I would like to share one major advantage in this:
Technically, VSTools Customizations will work pretty good with this SDI design. Earlier in v9.0, if we design a VSTools form, that would be shown outside the GP MDI. Worst thing, if we try to open a GP’s standard lookup, we would be seeing the lookup behind our calling VSTools form. And that’s quite absurd.
With SDI, VSTools form can also act like the regular GP form and it can also invoke the GP windows without any visual issues.
I guess, developers would have already noticed this and appreciated this changeover. But there could be other functional advantages in addition to what David has explained.
On the whole, I do love this SDI design for several reasons. And I have not got any one reason to hate it.