Obviously you're getting lots of varying opinions on this one. I've tried lots of different nymphing methods over 40 years of so of fly fishing and I still use a number of different systems.
I probably do 80% of my nymphing in a tightline, euro style. For this style, I just use a bright section of mono ("sighter") tied into my leader. This method is simple IMO. If you couple it with a large tungsten bead nymph you have a simple, direct system for casting and strike detection (no "hinge" in the system for floating indicator or added shot). But you need to get relatively close and keep casts and drifts short (I'd say 20'-30' including rod).
When I need a longer cast or drift to reach fish, I use a floating indicator ("suspender"). I carry and use several different types of indicators which I choose depending on conditions (and to a degree just how I feel at the moment). I have poly macrame yarn and both tubing (New Zealand style) and ortho rubber bands (Dorsey stye). I also have Thingamabobbers, several smaller foam indicators and, of course, large dry flies for dry / dropper use.
As for weighting flies / leaders, I've also used a variety of systems for rigging flies and weighting. I've rigged flies "in-line" and on tags. I've weighted flies (large tungsten beads) and with shot on the tippet (above, below and between flies).
My key suggestion is that there is no single, perfect system for all conditions. If you want to be successful nymph fishing in a variety of conditions, you should learn and try a variety of systems. Understand the pros / cons of each and what conditions they are best suited for.