Trying to understand the difference...

[GeneralZod]

I'm a BB Storm 2 user, who's heading to the land of Droid in late October and I'm trying to decide between the DX, Dinc and SF, with the DX looking like the way to go. However, I read on the SF forum where someone said the Fascinate is "completely open", whereas the DX isn't, giving the SF a clear advantage. Obviously, there are roots and ROMs available for the DX. So, is there a true advantage to this "openness" or am I simply misunderstanding. Thanks.