User blog comment:ClariS/Unofficial PBE Patch Notes (148)/@comment-218.186.15.10-20120916111222/@comment-218.186.15.10-20120918120215

I guess a simple stats buff would be easier to balance, but I just thought that a reduction of the Tumble buff duration to about 1s would be a cool idea as it allows her to tumble more often without increasing her damage.

Then again, any buff to her survivability would be good for the points you mentioned above.