EPQ can be time consuming depending on the other subjects that you take since some subjects require more dedication then others like art, especially if you want a good grade in a subject. If the subjects that you want to take is time consuming then i would consider the other qualification you mentioned, but the one down side i can think of is that a lot of universities might not recognise it as a qualification (it would then be useless/ not helpful and a waste of time), compared to an EPQ, which many do recognise. There are many ups and downs, but i think that if you are really passionate, have subjects that require not a lot of dedication then an EPQ would be good for universities and for life. But if your not passionate, the subjects require a lot of dedication, but it still seems kinda fun to take or you think it would be still good for you if you took it, then the other qualification you mentioned.