If you're doing this in your kitchen, stay far, far away from lead.
If you're doing this in your commercial building's electronics lab, where food and drink is prohibited, and there are only electronics people around... leaded solder is going to win.
If you're doing this in your factory, where your processes are tightly dialed in and you're moving mountains of product... now you can use either one just as easily, so there's no reason to risk lead unless the customer or application demands it.
Applications in the military and aerospace sectors are exempt from EU RoHS regulations. Some medical devices may also be exempt, but this is rare. (None of the medical devices I've worked on have been exempt.)
(The US generally follows the same pattern, by industry alignment rather than law. It's actually nice for the US: we get all the benefits of industry-wide RoHS adoption, but with the ability to painlessly "opt out" for any reason at all.)
If you're doing this in your kitchen, stay far, far away from lead.
If you're doing this in your commercial building's electronics lab, where food and drink is prohibited, and there are only electronics people around... leaded solder is going to win.
If you're doing this in your factory, where your processes are tightly dialed in and you're moving mountains of product... now you can use either one just as easily, so there's no reason to risk lead unless the customer or application demands it.