Varying Sets/Reps: Best Within a Workout or Over the Week?

I’ve read quite a few articles on T-Nation and I’m a bit confused whether its best to vary sets/rep within a workout or over the week. Some articles have you doing different sets/reps in the same workout, others keep them the same in a workout but change them on different days. Whats the pros/cons of each method?

e.g. some fullbody workouts are like this:
Bench: 5x5
Squat 5x5
Chin ups 3x8
Shoulder press 3x12
Leg press 3x20
BB curl 3x10

Whereas others suggest doing 5x5 for every exercise in workout A, 3x10 in workout B and 3x15 in workout C.

I’m just looking for opinions on pros/cons of both.

And using either method how would you periodize it for strength / hypertrophy / power?

The best is the scheme is the one that you find you are best able to stick with.

Assuming the program isn’t doing something odd like giving you 5x20 squats and 3x2 bicep curls.

The main difference I see is that in the first set up, every day is the same (heavy stuff then light stuff, every day). In the second set up, workouts are different (heavy day, light day, medium day).

Sometimes the first way gets to be a slow, monotonous grind. Or sometimes people really like the consistency.

The second way, with different days gives you more variety. And excitement. Some dudes really like one particular rep range, and look forward to that day. Or they like light day as almost a mini-break. Other people may hate this, and feel like it’s hard to focus on progress when you’re doing different stuff all the time.

To periodize the first setup, you would change the reps on the big lifts to something not 5 x 5. Basically you would use a less General and more Focused routine.

The second set up, with the different weights and reps doesn’t need to he switched much, because you’re already doing strength/hypertrophy/power work each week.

There are way more exciting and fun sciencey pros and cons of different arrangements, but that’s a big topic.

This sounds like something that would definitely work. Or put you in the morgue.

Just run through proven programs off this site over the course of the year. Great plan here…