The injectors tested in that picture should have been tested at rail pressure of 43psi. Testing below that is a bit meaningless, however you can see that they still have a nice V pattern and not a water hose.
Injector on the left is a scoob yellow top. Injector on the right is a stock RX7. That is a shit injector.
Decapping only removed the diffusion plate at the end of the injector. So it shouldn't effect the flow pattern too much when you mod them. If it does, something is wrong. I have read (but never seen) that some Subaru models come decaped from the factory...
99% of the 'decaps are shit' come from people who have never tested, looked at or are interested in the mod.
When I flow tested my decaps (wrx spec injectors), I also flow tested a set of sti pinks (550cc). I could not visually see any difference in spray patterns. However, I have no photographic proof so as far as the internet is concerned I could be full of shit
If you do mod your injectors, flow test them and have them sonicly cleaned and new o-rings installed. I've used Jordan Rover Tech for this before. Otherwise use le-Yellow Pages (United Fuel Injectors are another place).