I have a kayakpro speedstroke. The catch does come a bit late on that model because of the low pulley. Both of the models the OP is looking at have a high pulley, and also are more compact than the speedstroke. So they look to be big improvements on what was previously the gold standard.
Regarding the harshness of training on an erg, I suspect some of it has to do with how mind numbingly boring it is. I find I always go harder than I want to and keep increasing the intensity the longer I sit on it. I think subconsciously my brain realizes that pain and endorphins will ease the boredom. But don’t get the wrong impression about my level of dedication. By “longer” I mean about 30 minutes max on the erg. And by “usually” I mean almost never. Sure - every autumn I have the intention of erging all winter and being paddle fit when the ice goes out in the spring. But it never happens because I can cross country ski almost out my front door and that is just so much more fun than erging with the spiders in the basement.
Current Skis: Nelo Vanquish AIR, Epic V10g4, NK 670 double, NK exrcize, Carbonology Feather, Think Jet, Knysna Sonic X
Former Skis: Epic v10g3, Kai Waa Vega, Epic V12 g2, Epic V12 g1, Epic v10 double, Nelo 550 g2, Fenn Elite S, Custom Kayaks Synergy