I was wondering what the advantages if any in there 30mm scopes compared to there standard 1" tube take there 2x7 which wopuld be better .

The only true advantage is the 30mm tube will be stronger and allow for more windage and elevation. If you are looking at a 2-7x, I would go with the 1" tube.

Jon speaks the facts well.

Ironically, while the ability to have a greater range of windage and elevation adjustments is probably the greatest advantage of a larger maintube, the Leupold specs actually call for a NARROWER range of adjustment in their 30mm tubes for scopes of the same power. Of course, this may be an abberation in published factory specs, which are famously inconsistent with the actual specs of the real scopes.