There were tons of false transitions shown on the traces that did not exist in reality, and that prevented me from using it at all.
What's the current state of affairs in this regard? Are there any inexpensive logic analyzers with the shielded coaxial probes? This is usually not listed in the specs, and it is hard to tell from the product photos.
It can be a problem, one that can be mitigated by having a configurable threshold and also more grounds, best is one per channel. Another technique might be to ground channels and use a signal channel every other channel.
Setting a proper threshold can eliminate a lot of noise. LogicPort does this very well by having a variable threshold you can adjust. Others like the Saleae allow you to set the threshold for the logic you are using such as 3.3 or 5, etc., but know that sometimes what they might give you for 5v is not a true 2.5v threshold, but something different. This is where it is worth digging into the specifications a bit.
Having more grounds, hopefully one per signal near the signal is really ideal. The newer Saleae's have a ground for each channel for example.
You can ground unused channels so they aren't floating and toggling which could eat up your buffer memory if compression is used.
Honestly this was a problem for me initially with LA's to the point where I questioned how useful they could actually be, but I found the issue was the cheap models I was using. In the end I ended up with a Saleae Logic16 and also a Intronix LogicPort and have found that this isn't a problem on either one of these if I have it configured right.