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Re: 1997 UBC Deflection Requirements

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Can anyone out there please provide some insight to the 1997 UBC Story Drift Limitation? 
 
The 1994 UBC Story Drift Limitation (1628.8) limits the calculated displacement to 0.005 times the story height or overall height of the building for structures having a fundamental period of less than 0.7 sec. and 0.004H for T > 0.7 sec.  
 
The 1997 UBC Story Drift Limitation (1630.10) limits the calculated displacement to 0.025 times the story height or overall height of the building for T < 0.7sec and 0.020 for T > 0.7sec. 
 
Why would the allowable deflection be increased by such a large factor or increased at all?  The UBC Analysis of Revisions to the 1997 Uniform Codes states, "The drift requirements have been adjusted to be consistent with strength design requirements.  The primary change from the 1994 UBC is that the full inelastic response drifts rather than code force drifts are to be calculated." 
 
What is my maximum deflection for a simple k-braced frame?  0.025H seems too large to me.  Can someone decipher this for me please?
 
Andrew Arnold
Arnold Engineering
Junior Engineer
B.S. Civil Engineering
Cal Poly, SLO