To a degree price= quality. I would suggest the biggest gain someone might get, would be if you currently had totally worn out inserts and replaced them with any new/working ones. There is a jump again with different brands, but it'll be a smaller gain than the gain from going to stuffed ones to new ones.

the other thing is that to get it 'right' - even with adjustables - you really need the shocks to be put on a shock dyno and tested throughout their range of adjustment (if they in fact are adjustable) I've read an article or three where they did such tests and there was a significant difference from one to the other, out of what should have been a matching pair. And then sometimes the adjustment to make rebound stiffer (for example) made it softer, or paradoxically altered bump stiffness without affecting rebound to a certain degree.

So to get it optimal, you need to test em, find out which settings actually achieve what, and then try them and based on results adjust (if there is scope to do so) to get em fine tuned.

But again, the biggest gain will be replacing shagged ones with working ones.

It's also quite possible that the spring rate is too soft. If it has std springs, you can take that as a safe bet. For a streeter you'd tend to want double (or a little more) the factory spring rate. I've brought up in the past you can use the front springs out of a td gemini (you can use later ones, which are variable rate, but I prefer linear - just one of my idiosynchrasies/driving style etc). because the gemini has wishbone front, and the spring sits inward from the ball joint (whereas a strut front, it is right out there on top of it) - the control arm gets more leverage on the spring, and the spring has less leverage on the control arm, so the gemini springs are a lot higher rate. You'll still have to cut a couple of coils off the gemini springs to get the ride height down to a normal level, which then has the issue of not being captive if you jack the car up and the suspension droops all the way down. The solution here is to get shorter strut insterts. There is a page on the wiki about various part numbers. I have gotten a set but don't have the part # in front of me, I'll probably have to dig it up over the weekend). There's also a japanese performance shop type website that lists off teh shelf shortened strut inserts for the early 45mm strut tubes. I don't know if they are (like mine) off another car and happen to fit, or if they got 1200 inserts and machined the pushrod and re-threaded it, to remove some length.

http://www.datsun1200.asia/category/select/cid/318/pid/8889