I feel a bit like an expert on this topic, as most of my Shimano-equipped bikes have rapid-rise, aka lo-normal rear derailleurs, and I've been using this type of rear derailleur since its introduction as the XTR RD-M953 rear derailleur in…a long time ago. I'm committed enough in this particular way of shifting that I have a stash of RD-M960 rapid-rise derailleur spares.
To understand rapid-rise, one has to go back to when mountain biking was in its toddler years. That was in the early-to-mid 90s, around when Rivendell was born. Back then, to reduce the force required at the shifter (for both Rapid Fire and grip shift), derailleur return springs got progressively weaker. It got to the point when rear derailleurs would have trouble shifting into the tallest gear (smallest cog) when it was only moderately dirty. Then came the "fixes" –
Grip Shift bass worms, stronger aftermarket return springs that were near impossible to install, and other interesting knick-knacks that were usually CNCed and anodized.
Of course, an inability to shift into the tallest gear was bad for racing, so Shimano came up with the rapid-rise design to ensure that fingers forced the shift into the tallest gears, and spring tension shifted the chain onto the lowest gears. It worked very well, actually, as coincidentally downshifting works better with more finesse than upshifting, and the constant spring tension suited downshifting better than a panicky finger (as the cyclist realized too late that the legs+lungs were not nearly as strong as expected). The rumors about rapid-rise derailleurs being finicky is untrue, based on my use of many rapid-rise derailleurs from LX to XTR (but mostly XTR, so I may be biased). Neither were these more prone to failure or getting caught on trail debris, simply because they are essentially identical to derailleurs of the same era save for how their return springs attach. I'll admit that my fave, the RD-M960 does not come with a built-in cable adjuster, so you'll need that function at the shifter pod, or you'll need to install an inline adjuster; no biggie though.
All was not well unfortunately, because as good as rapid-rise performed, it also went against years of muscle memory of most cyclists. Soon, there were threats and riots, and Shimano was forced to switch back to high-normal, to preserve their domination of the mountain bike component market share. As I stated earlier, I run mostly rapid-rise on my Shimano equipped bikes, but I do have a few exceptions; for example, the M900 1st gen XTR gruppo on my Atlantis is obviously not rapid-rise. So there are occasions when I would miss a shift because I wasn't paying enough attention to which bike I'm on; but honestly, 5 minutes into it and I'm back to thinking about needing a higher or lower gear, rather than whether I should move the shift lever this way or that. It's not that big of a deal, for me at least.