Hola Kent, you may already be thinking this (but just in case), while the usage between LatAm and Peninsular Spanish differs as you say, whether the speaker uses the Pretérito Perfecto or the Pretérito Indefinido will depend on the time frame in which the action is set. In both cases it would be typically translated as “How long did it take you to do that project,” though it may be possible to use “has it taken you” in the Pretérito Perfecto. The former tense is used for “current” time frames such as this morning, this week, this month, this year, (note “this”) and today. So if the question is being asked within any of the above you will use the Pretérito Perfecto, where the time period is implied if not stated specifically. Traditionally this tense was used in Peninsular Spain to talk about life experiences “Has viajado mucho por Europa?” but nowadays the preference is to use the Pretérito Indefinido, which was always the preference in LatAm. There is a lesson about this on the course; search on “experiences.”

If on the other hand you are referring to a time period for the task that is definitely in the “completed” past e.g. “last week, yesterday, last month etc” then you would use the Pretérito Indefinido. 

I hope that helps. Saludos. John