fmic

WMI, if done correctly will always make more power, because besides having MUCH lower IAT, you will also have MUCH better timing.
As for running out - unless you're beating it on the track, you won't be using more than 3-4L per fuel tank. If driving long distance normally, you won't be using it at all.
I usually mount it in the windshield wiper tank and you use more fluid for the windshield wipers than for WMI in bad weather.

You can also have a proper WMI kit with failsafe and add switching to rear o2...

There is always much more potential with WMI. For those who have actually ran a proper WMI kit and tuned for it, this question is a total no-brainer.

So water meth it is. To be honest I’m glad to not have to add gobs of boost piping under the hood, nor am I a huge fan of the giant intercooler out front. Stock looking is way more my style at this point. Any preference on specific brands/must have features?? Amazon has a snow performance kit for $255 shipped. Looks like a simple on/off boost switch that I would set up for WOT boost levels is included with that kit. Some of the more expensive kits have a progressive controller, but it seems like the safety features built in to ME7 would make that unnecessary for spirited daily driving???

How well does the stock SMIC cool and what kind of pressure drop does it cause?

My preference would be to address poor intercooling with a better IC than to install a WMI kit.