I've done a couple of days with mine now. Actually I did a weekend in Houston with it right after it was released, but I failed to get the audio sorted for the in-car coaching. Even with that, it gave me useful feedback after each session especially considering that I was on a track I'd only driven once before.
I have to say that I like it. Like many intermediate drivers I have data capture (that I tend to ignore, or spend hours getting bogged down in). This really does cut to the chase. Think of it like having a Peter Krause looking over your traces and just picking out the ones with the biggest room for improvement.
Sidebar: wouldn't it be cool to have the same thing for OBD data? Don't make me wade through trace after trace, but send me an alert that says, "Hey, you're beginning to experience oil starvation on high speed left hand sweepers. Maybe consider baffling or an Accusump?" That's an actual example from one of his AiM seminars I was in btw of something that data can tell you but only if you know to look for it, and how to look for it.
Back to the Catalyst. Once I got the audio properly sorted, I have to say that I'm enjoying it. I ran it for two casual track days where I was working out of Harris Hill and jumping in to do a few sessions here and there. I know that track but its just been repaved and reconfigured, so it feels very different and most of my reference points have disappeared.
Its interesting. First, as a visual lap timer, the delta display is about as clear as you can get. Big, easy to read red and green background deltas meant that I always knew how I was doing (unlike the Solo that I've had mounted for far longer that somehow I always had to remember to check). The audio coaching was good too. 3-4 laps in it started suggesting "apex earlier/later." or "brake earlier." I had what felt like a few drop outs, where I'd just hear "later" without the noun, but by and large it was useful without being intrusive.
Did it help? Too early to say, honestly, since I don't have a good baseline on this track. My times did drop 1-2 seconds per session but I'd intentionally started out easy and kept dialing it in throughout the day, so I can't say that I wouldn't have done as well without it. I did feel that it gave me some interesting advice though, and following it generally seemed to work well.
Will it make me a better driver? I'll probably know that in another few weeks. I will say that its likely getting me back to my "current" skill level at that track faster than I would have progressed without it, but the real test will be how much it keeps helping me after the repave-newness wears off.
Still, I'm a Miata-driving cheapskate, and I don't begrudge the $1K. I'll likely be selling the Solo 2 as well. Not that it doesn't complement the Catalyst, but since I was rarely using it fully before now I don't see that I'll get more interested in digging out my own datapoints any time soon.
Lap times were consistently within 0.01 seconds between the two devices, btw.