Yamaha makes really high quality stuff for the price. The pickups in my TRBX304 were great, loud and punchy; the ones in my 604 are absolutely fantastic and I wouldn’t think of changing them out.
The BB734s I have tried sounded fantastic to me, I wouldn’t change a thing.
Several of my favorite bassists use them stock, both live and in the studio, and they sound great. The YGD pickups are just really good.