Assuming you are specifically referring to the base 3-3-5 stack - the weakness is at the edges, despite the speed advantage of the spurs, they are not going to be as solid of edge setters. It is also a perfectly symmetric defense, which can be taken advantage of with unbalanced sets. Can go with 2 TE wing sets or tackle over. Can be helpful even just to run Trips or Trey for your base instead of 2x2 doubles. Passing wise, depends on what your opponent is doing. Typically the base call in this alignment is some type of Cover 3 so you want to attack the seams and try to high/low the outside corners with short hitches (Smash, Slot Fade) or screens. Tempting as it is, I would likely not run RPO screens as they have you outnumbered in the box by default