The former. The problem is just that you've learned what the latter means better than the former. I'm the opposite.
Plus, the former is an absolute value where the latter is not, as far as I've been able to tell. I know that first span will always be 10pt font. I have no idea what "2" even means in this context.
That may be true, but regardless of whether pt is a best practice, the point remains that it is still a unit. IMO that puts it ahead of the alternative example.
Plus, the former is an absolute value where the latter is not, as far as I've been able to tell. I know that first span will always be 10pt font. I have no idea what "2" even means in this context.