XD pistols are somewhat controversial in the gun community; some love them while others feel they're not quite up to par with the other polymer wonders on the market today. I'll try to take that on one pro and con at a time as well as cover the specifics to the gun that is the subject of the review here, the XD40 ....
-Price. Before the current madness many base model XD pistols could be had for under $400
-Accurate. I've owned many XD(s) over the years and they're as accurate as any of their competitors in my experience
-Easy to maintain
-Easy to field strip
-Good amount of aftermarket support
-9+1 or 12+1 capacity
-Springfield Armory has excellent customer service
-Requires very little cleaning/lubrication to run reliably
-Fully supported feed ramp
-Loaded chamber indicator for ease of low light chamber checks
-Has an accessory rail for lights/lasers/combo units
-Trigger has a positive reset
-Reliability. As stated earlier, I've had several XD(s) and 2 needed to go back to SA for reliability issues. This one has been flawless however
-Detail stripping is more work than many competitors and relies heavily on roll pins. The striker retainer pin seems to have an unusually high failure rate which will deadline the gun if it fails when you lease want it to.
-The sights are machine pressed into the slide so if you want to replace them it's harder than most pistols. Do-able for sure but easy it is not.
-The bore axis is high for a striker fired gun
-Relatively heavy. The 40 SC comes in at 26oz unloaded vs 20oz for a G27
Here's a video with a little shooting, disassembly/assembly of the pistol, and a discussion of the pros and cons of the pistol.