Extar EP9 vs. Springfield Kuna: recoil impulse

As of today, I've personally finally fired a Springfield Kuna (rental at a range). I've owned an EP9 for a month. I can now say first-hand that the recoil impulse of the EP9 is lower than the Kuna, which surprised me.

Some caveats:

• This is my subjective experience. I didn't use any instrumentation to measure things.
• The weights are different, but close. The fully loaded weight of each may be different. My EP9 has an optic, a flashlight, an angled fore grip. The rental Kuna just had an optic, a hand guard, and no flashlight. The stock Kuna w/ brace weighs more than the stock EP9 w/ brace to start though, and I don't think my flashlight adds a enough weight to overshoot the ~1 pound difference in a meaningful way.
• A better A/B test would be firing them back-to-back. I haven't fired my EP9 in about a week, but at the same time I've put over 1,000 rounds through it so I have developed "sensory memory" for what it feels like to shoot.
• I used Magtech 115 grain FMJ in both cases.
• The SBA3 brace on the EP9 might be more pliant/flexible than the one the Kuna ships with, but I'm essentially comparing "default" setup of the braced version of both guns as they ship.

I guess I'm just a little bit surprised. I thought a roller-delayed firearm would be dramatically smoother than any direct-blowback firearm, even given a proprietary recoil damper and higher-mass bolt such as what Extar added to the EP9's buffer system. I can say at least with the Kuna, this isn't the case for my subjective experience. However, both guns are very easy to control and I'd feel 100% comfortable with either one in a self-defense scenario.

I'm excited to try other PCCs to compare. I love my EP9 for home defense and the range, but I'm still on the hunt for the perfect backpack gun, which is a niche the EP9 is ill-suited for due to its inability to accept a folding brace. (And no, I'm not going to carry a tennis racket bag to the grocery store in the winter and delude myself into thinking that everyone doesn't know exactly what's in it! "Hey, it's that guy who is always ready for a tennis match even though we don't have any tennis courts for miles and it's -5 degrees out!").