I do not really have a crusade against, but let me point out that at least some of you are living on a draw-backed technology mostly because of the available software for a few ATtiny controllers + direct MOSFET drive + 7135s. The drawbacks I am speaking of is lack of regulation and pulse width modulated lower modes.
Lack of regulation means the user needs to carefully consider and adjust lots of parameters to avoid overdriving emitters or just running them past their optimal points. This can mean tuning resistances for the whole chain of parts inside a flashlight.
PWM in lower modes may not be an issue, but it can be. And while MOSFETs can cope well with high frequency PWM, 7135s do not and their regulation goes out of whack. PWM and video filming is also a no-go.
Since I do not require the boons of ToyKeeper's software I opt for regulated linear or fully regulated buck/boost peace of mind drivers.
Cheers :-)