Even if you have 20% critical hit chance (and you probably don't), Antiprotons bonus give only extra 4% to DPS.
I actually have 3.5% critical chance - so replacing tetryons with Antiprotons will give me less then 1% general dps increase...

On the other hand I have relatively high level of Flow Capacitors, so Tetryons special ability do 292 damage to all shields (1168 damage total). Yes, it is only 2.5% chance, but my weapons (1 dual beam, 2 Dual Cannons, 3 turrets) do ~7.5 individual shoots per second total - So theoretical damage done by my useless tetryons ability is something like:

7.5*1168*0.025=218 extra DPS... (calculations are not correct since I am just aproximating probablility instead of calculating it, but error is below ~30%)

It is more then 1% given by antiprotons... Much more.