I dunno why you'd think tech 2 is good. Unless he's changed it it slows your tear speed to the lowest it can go, and doesn't change to your current strength.
So it's a constant weak laser that destroys your shooting speed. I get the concept- which is a constant lower damage that could be better than an occasional high damage- but in TBoI, it's all about that high damage hits that take out enemies as quick as possible.
I'm also p sure it kills your damage too.