I was recommended to try out the Xtrfy by jerrolds on Discord when I messaged him after searching for another right-handed mouse to replace my dying KPOE. After using the M4 for a week, I'm glad that I listened to him.
The mouse is pretty much as advertised -- a high-performing, lightweight, and comfortable gaming mouse. I mainly play FPS games and performance has been on par with my previous mice that featured a variety of sensors (KPOE, G203, G Pro). The shape is a good fit for me using a hybrid palm/fingertip grip style despite it being sculpted a bit more aggressively than the KPOE. The texture also adds to long-term comfort, as the M4 has stayed grippy even when my hands get a little sweaty. In terms of build quality my unit is solid and creaks only when I forcefully squeeze it. There's also no horizontal play on my left/right buttons.
Aside from the M4 purchase, I also had a really positive experience with deskhero. When I bought this mouse it wasn't even listed on the site just yet, but jerrolds was really accommodating and set up the product page for the matte black version I was looking for so I could place an order.
tl;dr -- positive experience with deskhero and the Xtry M4 is a great mouse.