First: I'm a Nitecore guy. I EDC three lights and they're all Nitecore.
10k lumens in a portable LED light is nothing short of amazing. This hobby has come a long way. The TM10K has a form factor that actually looks practical for someone to carry on their person, unlike most multi-emitter and multi-head lights.
Unfortunately, something had to give, and that something was pretty much everything. A non-replaceable battery that can't handle the load means a disposable flashlight, and no cooling fins to dump the massive amount of heat means that the advertised output is limited to seven seconds at a time. A few minutes is already pushing it - I'm sure we all remember the output graphs of a classic, unregulated incandescent flashlight, that starts out strong and quickly fades. Seven seconds abandons all pretense of practicality and goes for numbers. They might as well have supplemented the battery with some capacitors and gone for a flash of a fraction of a second. Then they could put an even bigger number on the side of the light, with even more exclamation marks...
And that's what makes this light so disappointing. Its entire purpose is to say "look, it's really small and it can do 10k lumens for an amount of time that isn't zero. EXCLAMATION MARK EXCLAMATION MARK." A practical tool doesn't have its specs plastered on the side in bigger print than the product's name, and it isn't covered in exclamation marks. Why pretend that this is intended to be a useful light?
The UI is typical for a flashaholic piece: tap the power button to toggle power, tap the mode button while the light is on to cycle through ascending brightness levels, off to low by holding the power button, off to high by holding the mode button, switch to high output then hold power and mode buttons to unlock the setting mode and then increase/decrease with power/mode buttons, use turbo mode by holding the dedicated turbo button. In short, a mess. Instead of a customizable "high" output level, why not just add an extra level? This kind of UI is why I stick to the SRT series, which has none of this "where did I put the flowchart" nonsense.
Don't get me wrong: 10k lumens in a light of this size is really cool, but I was hoping for the second practical light in the Tiny Monster series.