I used a logic probe in the '70s and may have occasionally found it helpful. They're still around now, and certain specific ones like the HP sets are quite sought-after as they're attractive historical pieces as well as being possibly useful.
But I don't use one any more, even though I have them. They're small and quick to use but give so little information compared to a scope - which I'm going to be using anyway 99% of the time - that looking for activity with a logic probe is an unnecessary stage. The complementary HP current tracer and pulser may have have additional uses but I find the pulser, again, not useful on a microprocessor system. It's useful to kick some random combinational logic or flipflop, but because it can't do that in sync with the processor it's not going to do a lot.
And I've also always wanted a Logic Dart. But they're not very common on ebay, and I often hear they're not all that useful : just a logic probe that displays a little more information ... I think I just want one because they're cute, have historical interest, and were things I lusted after back in the day. They used the HP48 calculator's LCD, which places them in the timeline alongside another desirable tool.
My go-to piece of testgear is the scope. Quite often before the DVM, unless I have a reason to check the power supply carefully. Most of the time the scope's DC accuracy is good enough for digital work and the instant information it gives me about clock rate, logic levels, noise, glitches etc. is streets ahead of anything else : maybe I use a logic analyser or the scope's mixed-signal features if the problem is complex.
I'm interested to know if other people's experience is different.
Do you still find these tools valuable ?
Is their low cost compared with even today's scopes an important feature ?
If you use them, what is your strategy ?