I think steady tempos should be left to the bodybuilders. From a performance stand point, i think you should be lifting as fast as possible and aiming to get stronger as quickly as possible and obviously with good form. This is assuming your goal is strength which you said it was for this workout.
This is a good point and research to back it up. One of the keys to increasing strength and power is the ability to push or pull the bar faster. The intent of pushing or pulling a weight faster has been shown to increase rate of velocity through neural adaptation...and increasing strength is all about nerual adaptation.
This information can be found in:
Effects of Velocity-Specific Training on Rate of Velocity Development, Peak Torque, and Performance. The Journal of Strength and Conditioning Research: Vol. 21, No. 3, pp. 870–874.
Dr Fred Hatfield promotes this as well with his "Compensatory Acceleration Training." That is all about pushing the weight as fast as you can regardless of the how heavy it is. You actually want try and throw the weight up.
I think for strength gains, lifting fast regardless of weight is important.
"Lifting fast" is imperative! However, another problem comes into play. Part of the speed movement in a bench press is devoted to deceleration of the bar. That meaning part of the movement involves slowign the bar down before lockout.
A couple of solutions take care of the deceleration issue. One is ballistic movments in which you throw the bar up into the air. This allows you to continue to accelrate the movement all the way. Bench press throws or medicine ball drops take care of this.
Another solution is the use of band chains on the bar. This allows you to continue to accelerate to the top of the movement.
I reckon slower tempos would only be useful, or optimal to you on 'endurance days' or maybe phases where training all the stabilising muscles was a focus.
Performing slow movements has it place. By eliminating momentum, you place more tension on the muscle. Thus, building more limit sttrength.
Also, if you've been stuck for a while, i would very highly recommend speed work for a few weeks atleast. Lifting at 40-70% of your max, low reps, high sets, very high speed - explosive. This will develop your Rate of Force development, or "explosive strength". I'm not a strength and conditioning coach, FYI, but surely explosive strength would benefit MMA?
While the intent in pushing heavy loads is important, it's not enough. To fully maximize power development, increasing rate of force development, you need to work with lighter loads to develop power output.
Research the optimal training percentages to be 46-62% of 1RM for increasing power.
The Load That Maximizes the Average Mechanical Power Output During Explosive Bench Press Throws in Highly Trained Athletes. The Journal of Strength and Conditioning Research: Vol. 15, No. 1, pp. 20–24.
With that said, the eccentric speed (how fast you lower the bar) plays a vital role in those training percentages. The faster you lower the bar, the more force you have to deal with...Force = Mass X Acceleration.
Research shows (Bench Press More Now/McLaughlin) that the force in lowering a bar too quickly in the bench press can magnify the load beyond the true weight of what is on the bar.
Novice lifters who lowered the bar too quickly, increased the fore fo the bar 49%. Thus, in bench pressing 300 lbs that would mean having to deal with 447 lbs of force once the bar hits you chest.
So, one of the important factors of lifting is the eccentric speed of the bar (how fast you lower it). This holds true for the squat and other movements as well.