I fall into the "nice to have, but not the most important factor, not by some way".
I was trying to think of a scenario, other than a manufactured one, where being able to see a 1:100000 glitch or runt would have been a useful feature recently, and I'm afraid I can't. My point being, by the time you're suspecting something of that sort you'll already have had a bunch of symptoms that would lead you to use other methods such as triggering to solve them.
One other point, it's a bit like the deep memory debate and how long is a piece of string: how much memory is enough, vs how fast an update rate do I need? It is very much the law of diminishing returns.
One thing I would say, though, is that even within the headline figures of updates/sec, this is quite often only under certain contrived circumstances, so be wary of that.
So yes. it's a convenient feature, but I think it's being overrated nowadays: given the choice, for example, between 10Mpts on all channels + 100kwfm/s versus 4Mpts shared + 1Mwfm/s, all other things being equal I'd prefer the former, but that's just an example, there are plenty of other things to consider than just update rate and deep memory, it is not a simple equation, and ultimately everyone will have different needs.