It seemed quite interesting until I had to apply the same upgrade(s) multiple times in order to unlock higher ones. (Although I'll accept I may have been doing that wrong, it isn't very obvious, but it is quite annoying.)
Imagine doing the same thing, but instead of improving the module every time you spend materials, it might take your modification in the exact opposite direction lol.
Once in awhile with the old system, you could roll a grade 5 modification only a couple times, and end up with a really nicely modified module. That's the one aspect I miss, sort of. The random godroll in the first few tries. Problem was, you might roll that same module 10-20+ times, and never see an improvement.
Post 3.0 engineering is consistent, and I don't think its a bad thing, even if it might take more roles than it used to (if you were blessed by the RNG, of course).
Edit: It was easier to slap a bunch of g5 parts on a ship really fast back then, as long as you weren't super concerned about having the 100% best numbers. Having to upgrade all the way up through the tree is a bit of an annoyance, but its really the last two tiers that seem to be super greedy.