Efficiency Question Region3 vs Vector Math

So in a game, I need to work out if a player is within a certain space. Im torn between using region3 or using a part and checking if the players’s HRP is near using the following code:

function module.CheckIfNearXYZ(Part1, Part2Position, Leniency)
	local relativePos = Part1.CFrame:pointToObjectSpace(Part2Position)
    if math.abs(relativePos.X) <= Part1.Size.X * Leniency * 0.5 and math.abs(relativePos.Y) <= Part1.Size.Y * Leniency * 0.5 and math.abs(relativePos.Z) <= Part1.Size.Z * Leniency * 0.5 then
         return true
    else
	    return false
    end
end

for the sake of the example Leniency = 1.

What do you guys personally use and recommend?