Even if were upwards of 5 seconds difference and a 1,000 splices... you've saved a 1.2 hours. It's money, but I'd hardly call that considerable.
I'd be willing to invest that extra 1.2 hours of labor to get my guys on some solid splicing methods.
I do acknowledge that it depends, as
@brantmacga pointed out, on the skill level of your guys. I was thinking about it from my own perspective as someone whose never used anything but wire nuts and takes perfecting his splicing techniques very seriously.