No one size fits all, also distance matters and is it a pile of wet logs or a mcdonalds bag at your feet?
Sometimes spreading out your beam and pumping heat into the medium prior to exceeding flashpoint is needed or it goes out.
You need convergence but also total energy for certain things.
Humid double wall corrugated cardboard boxes will light and go out again and again, but thin wall cardboard will light once it's penetrated.
As far as the nubm44 the nubm06 is being tested and may edge it out as emitter size and efficiency might be slightly better, it's in testing but either needs beam correction if any distance is involved.
What works best is convergence of more power.
A 405 stays tight further, but it wont light a corrugated cardboard box at 25 feet or 10 feet or 5 feet if it's humid, there's not enough total energy, burn a tiny hole yes but it can't get enough total energy into the medium to sustain combustion.
Well focused multiple beams that are adjustable will cover the most situations the best, or 1 big sob that can be defocused for some jobs.
Cutting branches takes some power, and at distance focus and power.
It all takes more than you think, and small heat sinks get hot faster, duhh right, well a lot of people realize later they wanted more run time.
I like the nubm44, but I like the nubmo5t and numb06 price better.
It really depends on your purpose, more power is always good and you will often need more than you think, just burning a box at 30 meters takes a lot more than you might think.