glamdringfh :
More than anything I think it comes down to:
-Do you have space in your case for the extra water cooling feature?
-Are you planning on overclocking the GPU so much that it might justify putting a water cooler on it?
One issue with overclocking is that the 980 ti hybrid still uses the same vrms on the reference gtx 980 ti, so high overclocks will be difficult. Where as the air cooled Classified edition will overclock way higher.