The driver is the most forgiving club in the bag, the biggest face, and it's on a tee. For me, I have a much easier time with it and I've been hating fairway woods and hybrids lately. Better for me to take a big rip as long as there's no big trouble. If I choose to make a safer (shorter) tee shot, I'd hit a long iron. If I can't hit my driver, no club will go straight. Unless there's OB or a place to lose balls, I usually just hit it and play trouble shot roulette. I usually hit fairways, but on the occasions the course architect wants me to lay up I sometimes hit it even harder. I only listen to the caddy in my head if it costs me money, time, or actual strokes, and am less concerned about positioning and bad lies. No point in neglecting my trouble play, plenty of golfers are great from the fairway but crumble when they miss it.
On the other hand, the 3 wood is more workable at times, especially high and low, and there are some fairways that just aren't deep enough for a full drive. Part of it is that I need to regrip my current 3 wood, as I hate the Winn grip, it feels like it's made of Nerf. My 44.5" driver feels short and light and has a really big looking head, as well as a cord grip; this fills me with confidence. On the other hand, my 3 is 43.5", has a normal head and a winnlite soft grip that slips and lets me feel the shaft under it. Add that to the fact that it feels super long when soled, and my main problem is fat/thin contact, I don't feel particularly confident off the tee box with it. With the driver, I can just swing hard and not hit the ground, and I have 4in^2 of forgiveness.
I feel my swing is a lot more repeating when I use some force/athleticism, and I can feel what I'm doing better when I need to commit to it. If I make a softer swing, I really get lazy, especially with my footwork and release. Many people have the opposite problem, and using a club that's not the big stick helps them make a more correct swing without trying to get power from improper mechanics. I also drive well because I know it doesn't matter much; I'll blade my 50 yard pitch to hit the green anyway, so why not get as close as I can? (My wedge game isn't too bad on its own, but I really seem to screw up every time I hit a good drive. The golf Gods don't appreciate my hubris.)
Whatever makes you focus on your swing the most is the correct shot. In the end, 20 yards between the 2 clubs is little difference to one's score, so either can be a good play. I'm convinced that it's not the clubs or the swing that make a golfer great; it's the focus they have on the moment. It's true in any sport, you could send Justin Tuck around the side of the tee box, and a guy like Hogan or Greg Norman or Nicklaus will still be focused on the shot. Mind you, that's a situation where it might be smarter to move... On the other hand, once any player loses his mental focus on his round, all hell breaks loose. His focus goes to the prize money, the other players, the fans chanting his name, and he shoots an 82 on Sunday. There's a reason many people would rather make a charge than hold a lead, and the fact is that with a lead you have a lot more pressure on you, while making a charge is a determined, shot by shot effort.
For us amateurs, often this sort of focus gets in the way of enjoying the round, or we simply don't care. But adding in the factor of an uncomfortable club isn't helping either way.