What's the point of PSK125? I just finished a session running PSK31 on 15m (which was really lively, by the way) when I thought I'd just check 10m to see if anything was going on up there. I soon found that there wasn't much. The waterfall was devoid of traces, apart from a weak, wide, nebulous trace which proved to be PSK125. PY2DN was calling CQ, but try as I might he couldn't decode me.
It appeared that he was making some QSOs, presumably with people enjoying better 10m propagation than I had. PY2DN's signal was far from perfect copy. Most times he transmitted I received mostly garbage. But I'm sure there was enough energy in the transmission to produce solid copy had he been using PSK31.
I guess the point of PSK125 is speed. PY2DN's CQ and my reply both lasted about two seconds. But what's the hurry? Not only can I not type that fast, I can't even click macro buttons that fast. So the time saved is for nothing. I accept there is a role for PSK63 in contests, when speed matters, but only when signals are strong enough to provide good copy. PSK125 is a step too far. It spreads the energy too thinly.
I've tried loads of new digital modes but I keep on coming back to good old PSK31. I find it more satisfying in the long run. There's tons of activity from heaps of different locations. You can often find a PSK31 signal when the CW and SSB band segments are dead. PSK31 is a real QSO mode where you can actually converse with somebody and exchange information with them. And you don't need to run a kilowatt to a huge tribander to be successful. I was calling CQ on 15m with 40w to my attic dipole and I felt like a big gun: I was getting replies, including DX replies, to every other call.
I think PSK31 has earned its place alongside CW and SSB as one of the staple modes of amateur radio. Other modes are just for temporary amusement.