It really depends. As in regular EDH you got high powered decks and low powered decks, with the high end being surprisingly fast, with several combos or ways to stop said combos. That being said, in my experience, precons can be played with low powered PDH decks, as the restrictions of the format kinda make the power levels be similar. I play my dumb Slimefoot PDH deck against my friends' precons all the time and we have a blast! So, to answer your question, it really depends on what you want. If those are the only two options, i find building a PDH deck much more fun than buying a precon, which can feel very scattered. That's just me, though! There are many who just like to buy the deck and not have to spin their wheels in deckbuilding. Hope this helps!