Dynamic tension sets work, period.
The issue MAY be that, since there are only finite hours in the day, how does one decide where to focus one's energy?
Are there more effective methods of strength building?
Yes, there is no debate about this ( or at least there shouldn't be since we have empirical evidence for this).
The thing is that, dynamic tension builds strength ALONG the range of movement in a far more direct manner than typical strength building.
What I mean is this, and using the "pushing" motion of pushing you arm away from your chest as an example:
Do a bench press or push-up and you have a set pathway that, while CLOSE to a punch, is NOT a punch, so you will strength all the muscles involved in punching in a GENERAL way.
Dynamic tension strengths the muscles in a SPECIFIC way since you are actually doing the punching movement EXACTLY as you would when punching ( albeit slower and with tension).
It is NOT a question of better or worse, it is simply DIFFERENT.
Ideally, do BOTH methods ( kind of a no-brainer when you think of it).
Now, the issue of 90 min.
There is an inverse ratio of time VS intensity, in short, the more intense an exercise, the LESS time you can do it for ( think an all our sprint VS a paced run).
Logically speaking, if you can do ANYTHING for 90 min, it is NOT that intense.
I do the Iron Wire and, depending on what I wish to work on at the time, it can be done for strength or for conditioning or for relaxation.
There is a very different FEEL to dynamic tension and I find that it COMPLIMENTS my general strength training very well.\
And that is the thing, dynamic tension sets were NEVER designed to take the place of general strength training BUT to COMPLIMENT it or even to supplement it when using ST devices was not possible.
Historically speaking, strength training devices were ALWAYS used for building general strength while specialized sets and such were used to develop SPECIALIZED strength and conditioning.
Psalms 144:1
Praise be my Lord my Rock,
He trains my hands for war, my fingers for battle !