Ended up having Amazon send me a new K60. I'll return the first one sometime next week.
There are some interesting differences between the two K60's. These are my observations and thoughts after looking closely at and using both side by side.
- The first K60 has a very noticeable dark spot in the center of the hotspot. It is clearly visible both indoors and outdoors, even at long distances against tree lines or buildings.
I assumed this was to be expected because of the quad die XHP70. But the new K60 does not have any dark spot in the hotspot. Not on a wall, not outside, none.
- The hotspot on the first K60 is surrounded by a square-ish corona that is slightly yellow.
Again, I assumed because of the XHP70. But the new K60 has a perfectly circular corona, and it's white.
- Between the two K60's, there's a considerable difference in the nylon ring that is between the LED and the reflector.
The ring on the new K60 has a wider outer step and a steeper approach to the LED on the second step. This change is (imo) the reason for the improved beam and corona on the new K60.
- After running on high for a few minutes and being turned off, the LED on the old K60 will glow faintly for a minute or more.
The LED on the new K60 does not glow for more than a few seconds after being turned off.
- The magnetic control ring on the old K60 was gritty on the first 4 settings and smooth as ball bearings on the last 3 settings.
The new K60 is smooth and consistent through all settings, and overall the stops are much more positive and definite.
- The markings and lettering on the new K60 are whiter, brighter, and much more crisp in their application.
Nothing was wrong with the old, but the new just looks better to me.
- The new K60 is enough brighter that it's noticeable. I'm guessing the new K60 appears and meters brighter because it's without the dark spot in the hotspot.
The new K60 is 18% brighter on Level 5.
The new K60 is 7% brighter on Level 6.
Tested it twice, and after swapping batteries in the lights the results were identical using Evva 3500mAh NCR18650GA protected cells (10A with 3 MOSFET).
The pic below is the old K60.
The pic below is the new K60.
The new K60 is on the left in the pic below.
The new K60 is on the right in the pic below.