Have had the IV Plus for about a week now, and here's my take.
Other Zebralights I own are the sc600 III HI Plus, the sc600Fd III Plus and the sc5. The majority of use these lights get for me is when I'm at work. I work on a drilling rig, and often at night, so a good, high powered, compact flashlight is useful, because there is a lot of ambient lighting, but with spots that still need to be lit up to see properly. I've used all of these light for work, but this week I got called out to help out on a well control situation for 3 nights straight, and got to put it to use.
Before this light, I would carry both the HI and Fd plus for my needs out there. The Fd was wonderfull for working close to light up a work area and avoiding reflection of hotspots back in your eyes. I would however have to run it with pretty high power to be able to see well enough, therefore reducing runtime. Color rendition obviously is great. Lighting up distances, or down in pits it struggled. In these areas, the III HI excelled, but of course for close up didn't light up as wide an area and thenreflective hot spot will blind you. Even with it's narrow hot spot, and ability to run it a little lower, I'd find its run time would still sometimes come up a little short. Not terrible by any means, but for my uses, the IV plus seemed to outrun them both.
First of all, I set the G6 with quick click for lows, and long hold for highs. Double click is still mediums. I actually think this is even better than the standard zebralight setup. To get to medium you avoid the bright flash, and at any brightness you are on, you simply hold for brighter. Easier to explain to people if they should need to use it. I used it quite extensively for the three nights, alternating between the medium at 170 lumens and high at 350 lumens, and played with H1 at 2300 several times because its new of course. The difference between 170 amd 350 isnt hugely significant, but the 350 can offer just a hair better light up and avoid the PID. For most uses, the 170 works perfect, and even though it's significantly floodier than the HI, it still offers plenty enough throw to light up in a well lit place. With all that use, and messing around with H1, I came home and voltage was still 3.93 after 3 nights. Extremely satisfied with that efficiency. This is with a Sony VT6, so should even do better with the Panasonic at 3500 mah.
As far as white walling it, yes the corona shift is noticeable indoors, and its got a hint of yellow to it. Not near as nice a color as the Fd plus, but it works, amd outdoors, this becomes less noticeable. On a side note, when comparing to the sc5 for tint and hot spot, it reminded me how nice the tint and beam quality is on the sc5. Clean transition from hot spot to spill consistent beam color, and a beautiful rosy slight magenta tint. For a non high CRI light, the sc5 is awesome. Run times for my uses, just don't cut it. For the house though, it is the perfect light.
All in all I love the IV plus. For me its two lights in one. The HI and Fd plus. Both of which I'll keep though, because they excel at their given purpose. Throw and beautiful high CRI flood.
Satisfied again by Zebralight.
