trying to decide between Aquamist 1s and 2s systems

[zsz2k]

I understand the difference between the two; my question is, without a dyno to tune the 2s system on, are there still obvious performance benefits?

The manual itself states that water injection doesnt' follow a fixed ratio like air/fuel. The 1s system is easier to install and cheaper - so are there real performance gains to be had from the high end system?

I should probably rephrase this: how well does the system need to be tuned before the 2s system shows notable improvements over the 1s system? And the second question is, how hard is it to fine-tune the system to give these results if you don't have a dynamometer?