I have an incan 6D from 1982 and aside from the output have always found it to be too long and cumbersome for me. I think the sweet spot for the ML300L is the 3D or 4D. I purchased a ML300L 4D in 2024 and have come to really like it but I do prefer the 3D size. Either way, take a look at this evaluation of the ML300L 4D and 6D.
Maglite Runtime Sorcery (ML300L 6D) and 4D Version
Not 'on-topic', but the talking horse told me I should not link to material on other flashlight sites. I personally don't mind and think it's appropriate sometimes (as in this case); but just an FYI;-)