Alright, I borrowed my father-in-law's XD-S for a few hours of testing and comparison. Here are some (cell phone) photos of my XD vs the XD-S. My XD .45 ACP has a 4" barrel with the compact, 10 round capacity grip.
Initial Impressions
The XD-S was much more compact than I expected from the pictures on Springfield's website. Unfortunately, I didn't have the other back straps for the grip, because I would have preferred to have the next size down from the biggest one. It was very light and thin. I like the fact that it doesn't have the exposed striker in the back. I've put a hole in several t-shirts while sitting down. As I'm sure ya'll have seen from stock photos, they've done a great job with detailing. I like how the back of the slide is sloped rather than flat.
Range Time
I went to the range and as luck would have it, they had a Glock Model 36 for rent. I've been comparing the XD-S and G36 for my next carry pistol. The G36 is on the left in both photos.
Sorry about the crappy second photo. The lighting and the gunsmoke haze didn't exactly help. The G36s barrel is about half an inch longer. The difference in weight between the two was so close, but the G36s slightly longer barrel gave the XD-S the edge on balance/weight distribution. I was shooting at 5 meters (I was doing an initial test, not an action movie) and I was able to get tighter groups with the XD-S over the G36, but not by much. My father-in-law told me that when he first bought the XD-S he had problems chambering rounds, but firing it helped. I guessed the feed ramp just needed some smoothing out when it was brand new, but I personally had no issues. The G36's grip was perfect for me, but if I buy that, I'd put a Hogue Hand-all slip on grip like I have on my G19. The XD-S has a grip safety, so that's not a possibility. The XD-S has the plastic detailing on the grip, and I found that the detailing on the back strap would dig into the palm of my hand some. This might have been solved by the slimmer back strap, but I didn't have the option to swap out. If you have a larger hand, the G36 is going to be better for you simply because the XD-S will be impossible to hold. The G36 magazine has a small lip to accommodate a little finger. Like my full size Glock and XD, the Glock wins in terms of slide smoothness and chambering, but the XD-S was much better than my XD-M. Also, the short barrel on the XD-S required locking the slide to the rear before chambering a round; I misfed probably 50% of the time trying to pull and release, even though I made sure to draw it all the way back and not ride it forward. Both pistols will fire a chambered round with no magazine in the weapon, if anyone is curious for safety's sake. I shot 50 rounds through each pistol and had zero malfunction or misfeed of any type. I fired several Speer 200gr.+P JHP rounds...whew. That was a little rough compared to the 230 gr FMJs, but if it was life or death, you'd never notice.
I'm going to buy one of the two, so which would I choose? I don't know yet. They were so closely aligned in performance and size, I just don't know. The XD-S is clearly a better
looking gun. It might come down to price. I will have to shoot them both again and think about it some more. The G36 definitely gets a point for being 6+1 versus the XD-S's 5+1.
If you have any questions, feel free to ask.