Tenser's Transformation: worth it?

[Ligraph]

Been working on a Tenser's Wiz/Art build, so I decided to do some dps calculations with Tenser's and without it on my EK Sorc. Only did 5 dummy kills each way, but the data was fairly cohesive, and averaging results found only a 6.86% increase in DPS from Tenser's.

Data:
Time to Kill:
no tenser's----tenser's
16.7-----------15.24
16.43----------16.28
16.65----------15.36
16.34----------15.35
16.64----------15.16
16.61----------15.39

Averages:
16.56166667---15.46333333

DPS:
301.9019825------323.3455486

% Diff
6.859224564

This seems extremely low, especially for a teir 5. Is this a normal amount? Or am I missing something? Also, if anyone knows of a better way to format tables... please tell.