Noone competent runs 3-3-5 base, it's too vulnerable against the run. The alternative is a 3-4, but both schemes if done right will employee a platoon of LB/DT/Ends and sub/adjust based on opponent scheme/personnel/down and distance. And it's essentially operates as a disguised front 7 that can play as anything from a 5-2 to a dime post-snap depending on the ends/OLB responsibility(rush edge, spy, drop into zone). But the modern 3-4 typically typically runs as a bear front with a 3 tech, 0 tech, and 3 or 5 tech down, and then walks up 2 OLBs near the edge. The end result is something that looks like a 5-2, but can drop to become a 3-4 and causes chaos for the OL because which of the 4 LB's are rushing and dropping can't be determine until post-snap. But the 3-4 is extremely vulnerable to running QB's
The 4-2-5 is nowhere near as vulnerable vs a mobile qb, but is not as challenging for QB reads and OL assignments and is weaker vs power. It's also much more personnel-heavy and requries 2 pass rush specialist edges like Simmons/Moore/Orogbo that can also drop/cover the flat, 2 traditional 5 tech DE that are strong enough to fight off tackles and set the edge/maintain B/C gap integrity while also being capable pass rushers(Lance Jackson/Sorrell/Burke/Vasek), 1 traditional 3 tech that's a run stopper first, but can get pressure occassionally(Collins, incoming Charles), 1 0 tech whose only job is to eat the center and both A gaps in run defense(Norton, incoming xfer from UNC, inc freshman Sharma), and a do it all DT that can play anywhere on the line and is the one making tackle for loss in run defense, getting sacks via interior pass rush an can ideally move out to D-end to play as 5 tech for bear fronts(Broughton, inc frosh Justus Terry). And that unit has no weaknesses as it can be mixed and matched to form a down 4 that's capable of defending any and all scenariors/personnel/scheme