Having had both the Hellcat and XDS Mod. 2, I must agree. We originally purchased our non-OSP Hellcat for my wife. unfortunately, we quickly figured out that with her arthritis, she could not easily rack the slide. Meanwhile, I picked up an XDS Mod.2. When I shot them side by side, I much preferred the feeling of the XDS, and it shot more accurately.
I installed a DPM recoil spring in the Hellcat hoping it would make it easier for my wife. Soon came the Apex trigger and PRP internal spring kit. Still, she couldn't rack the thing, even after I'd run 500+ rounds through it. At this point, we stopped asking what we could do to make it usable for her and started looking at something like an EZ.
Okay, I inherited a new toy, a toy everything I read said was awesome, so investigated what else I could do to the Cat. I installed a threaded barrel as a suppressor was always part of the long-term plan, and added a Tyrant Unicomp to tame some of the recoil. In the end, except for cutting the slide for an optic, it got about every mod available. The spring kit and trigger I loved, made it a much more comfortable gun, but the funny thing was, I still didn't love it as much as my XDS. The only advantage I saw in the Hellcat was capacity.
I stopped and added up what I'd paid to upgrade the Hellcat, WOW. All this time I had planned to replicate this on the XDS, but when I looked it, it was a hard number to stomach, plus XDS parts weren't as readily available, I felt like my hands were tied. I started looking for something I could buy that already had much of what I did right out of the box. An XDM Elite was my target...then the PDP appeared on the market. A PPQ was at the very top of that "What I want next" list.
I talked to a lot of people at all the LGS and posed the question, "XDM Elite or PDP?" I was honestly shocked when even the people that didn't carry Walther ALL pointed to the PDP, a few who didn't carry Walther offered other "in stock" options, but between the two said PDP. I sold the XDS and put that into my PDP C4, a gun that was beautiful to shoot from day 1. I don't for a second regret the choice of replacement, just the gun I sold to get it.
Even today, I have just never fallen in love with the Cat and miss the feel of the XDS. Every time I take the Cat shooting, I feel more and more like I just don't want to be bothered with it anymore, but when I look at the loss I'd take. I feel like I'd dug myself in a hole with it and am stuck with it.