The Gravity, more than likely will be replacing the Domination in the Premier line.  I think both would fall just under the BW Solid though, well at least a newer BW S, one that's still going strong.  The Dom is the last of the RAD weight blocks.  It definately is under the Attitude as it's a pearl & that's what the Gravity is.  Dom's are getting harder to get & are costing more money now that they've almost discontinued them.  There are, however, some pro-pins &/or Pro-CGs out there that are more available & cheaper (see bowlingball.com).  But I'd go w/the current ball coming out, jmo.
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"The last time I saw a face like yours, it had a hook in it's mouth."