With irons I am definitely a club up guy. Swinging harder does not produce the desired results for me while swinging easy doesn't seem to penalize me in distance. With driver, though, I can swing a bit harder and I have found that doing so helps me clear my left hip better.
More club.
I use yardage to the back of the green. I probably go over the back of the green 10% of the time.
I started doing this 3 years ago. Dropped my handicap by 5 strokes.
Swinging harder results in bad things for me...
I've tried clubbing up and choking up on the grip... but I don't see an actual change in anything.
For example... I hit a 7 iron about 155. If I choke up on a 7 iron (3-4 fingers up the grip), I still hit it about 155. Sometimes it results in a thin shot that goes 170.
I must be doing something to negate the shorter club.
I learned to just choke up a little on the club if I need to hit a half club shorter and take the same swing. Wedges? That's a different game. Half-swings and shorter are part of the game.
I did find out recently on the launch monitor that I go after the ball at 90% full effort. More errors happen when I use a lot less than that or try to kill it.
I take more club and swing easy. Nothing good comes from over swinging. All my shots are normally in the 85/90% range on full shots. You have to leave a little in the tank for the must carry shots. Going all out leads to bad tempo and trouble for me, so I don't go there. I have zero golf ego's. I don't care that someone else is hitting two clubs less than me say on a par 3. I just play my game.
More club, I've always remembered a Jack Nicklaus line that essentially said you will likely only pure 2 to 3 shots per round so why play every shot as if you are going to pure it.
I don't swing harder because I can flat out lose all control doing so (what little control I have). I don't swing easier either because I get out of sync which leads to its own unique problems.
I go for the longer club and if it's too much club I shorten the shot by a combination of narrowing the stance, gripping down, or shortening the back swing (depending on how much I think I need to take off).
For the first time in my golfing history I am actually going more club. I have always been the swing harder type. Usually with Phil like results. Spectacular results and spectacular failures. I'm scoring a whole lot better these days by a wide margin.
I've learned to be more of a tempo golfer than a swing harder golfer. That said, I don't see the trade-off as "more club or swing harder". If I swing hard, my 7-iron goes 155-160. If I swing softer, with better tempo and sequence, my 7-iron goes 175-180. So, for me, if I am in tempo, it's "right club" rather than "more club."
If more club will do what I need it to do, then that's the only thing that makes sense. Why swing harder than normal if you don't have to? Even if I'm between clubs, it's easier to back off on a longer club by just choking down an inch or so and making my normal swing. Overswinging mostly just results in problems.
I am a more club person. I feel more comfortable taking something off my swing and it is also fun to mess with some of the guys I play with. It really throws them off their game when I hit something like a half 7 iron from 125 instead of blasting a gap wedge.