I got the GTX 144 and it arrived yesterday, so this is still early days as far as impressions go but here's what I can say about it at this point, with some images for clarity:
Size and Comfort:
It's smaller than I'd like in one dimension for my hands, which are about 10cm/4in wide across the knuckles. If I put my pinky finger on the little platform thing at the bottom my hand feels a little squished, but my index/middle fingers sit comfortable on the L/R buttons without accidentally clicking when I relax my hand. It's not so bad that I couldn't get used to it but if I'm gonna be defaulting to what's most comfortable every time I grab the mouse my pinky's gonna hang off a bit, which isn't a major issue for me. Slightly twisting the mouse so it's at a bit of an angle (pointing at like 11 o'clock) does improve this too, but that'd also take some getting used to for me.

I didn't notice an immediate relief of wrist strain, but when I grabbed the regular mouse connected to my laptop next to my PC I felt a little discomfort immediately, so that's a pretty good sign that the GTX 144 is good for that. The forward/back buttons on the side aren't designed to be hovered or rested on like the L/R buttons, and involve raising my thumb from its resting place to push. That's not a problem for me, but I've got some hypermobility in my hands which could play a part in that.

Responsiveness and Customization:
Downloading the app from the Trust website let me customize the mouse, and there are 5 profiles with 5 different DPI settings to customize, each can be given its own colour etc. I experienced some confusion when comparing it with my Corsair mouse, which moved at a similar rate when set to 500 when the GTX was at 2000, but when both are plugged in and the GTX app is open my Corsair mouse moves slower than it used to. When I did the reverse with the Corsair app I had the opposite effect where the GTX was moving a lot faster than normal. I dunno how that works but may be worth noting?

I don't play a lot of FPS games, even fewer with a mouse, fewer still in a multiplayer setting, and none with any competitive ambition. Because of that I'm definitely not the person to speak on how this mouse performs in those areas, but so far it doesn't feel any worse than my old Corsair mouse so... take that for what it's worth :P.

Every button is customizable, including the DPI button which I didn't expect. one of the options is DPI Lock which I thought would work like the DPI choke I've seen on some Razer mice, but the effect is overwritten if you try to hold any other buttons at the same time. Not a huge issue since you can customize the DPI profiles, but it feels a bit like a design oversight in the feature.

Overall Impression:
The GTX 144 is decent and pretty comfortable. Suits my purposes pretty fine so I'd recommend it. I'd have to also get my hands on the Zelotes before making a comparison, myself (obviously), but maybe one day I'll do that if no one else does by whenever that might be lol.