I'm not a very good drafter, so for me I'm gambling if I go outside the box too much. 17/40 is a pretty good place where I feel many limited style decks will do well at (mine at least). There are certainly times I feel 16 or even 18 is the right number, and maybe in those cases where I'm not sure I should bump to 41 and go with the higher land number. Not sure. I dislike uneven card numbers though as my pile shuffling isn't even and I end up thinking someone has one of my cards or I have one of theirs.
What I do know is that 95% of my Magic experience is constructed, and my version 1 mana base in virtually every constructed deck I made was suboptimal and I later tweaked it after much play time and testing. And that's the problem with limited and cube by extension. I'm basically stuck with my version 1 build for the night. Not that I haven't made tweaks after I got slaughtered in my first match, but it's the exception to the rule. And a handful of games is insufficient to dial in a deck even in the most ideal of situations, so it feels a bit like over engineering to try and get crazy with building mana bases thinking I'm squeezing more efficiency. I doubt I'd be doing that the vast majority of the time.
What I do know is that 95% of my Magic experience is constructed, and my version 1 mana base in virtually every constructed deck I made was suboptimal and I later tweaked it after much play time and testing. And that's the problem with limited and cube by extension. I'm basically stuck with my version 1 build for the night. Not that I haven't made tweaks after I got slaughtered in my first match, but it's the exception to the rule. And a handful of games is insufficient to dial in a deck even in the most ideal of situations, so it feels a bit like over engineering to try and get crazy with building mana bases thinking I'm squeezing more efficiency. I doubt I'd be doing that the vast majority of the time.