I have a little LC9 that has a SS guide rod (actually did the testing for the first one ever made for the LC9 on my gun and wrote up a long report on the ruger forum. Got bashed a bit because they thought since i was "testing" a part because i HATE plastic guide rods for the exact reason because they can break like mentioned, so i decided to call around and found a shop that would make one as long as i sent him a stock one so he could get the measurements. It was claimed that i was "associated" with the company when i was just trying to help out the community by testing out an aftermarket part to get more out there so there's more options, and a lot of people were really thankful which made up for the other half that thought i was just doing a sales pitch LOL.
Anyways, IMO they're 2 completely different guns. The LC9 has a horrible trigger pull that takes a lot of dry-firing/range practice to get used to (once you do though the gun is SURPRISINGLY accurate! At 7yds. i can shoot a ~3in. grouping) that trigger pull. There is a fix for out out now i believe that reduces the trigger pull/travel however.
I've had nothing but good experiences with my LC9, it's eaten ~2k round with only 1, yes, 1 FTF and that happened within the first 50 rounds, so i count that as break-in. Other than that no problems at all but IMO the gun is strictly for up close protection, or if you are carrying someplace where you REALLY don't want to accidentally be seen carrying. It is hard to aim accurately since the sights are so close together, with the combo of the trigger pull, it takes a lot of practice! I carry my LC9 when i'm mountain biking since it's lighter and if I'm wearing more dressier clothes and going out to dinner or something. If I'm going to be hiking or out and about doing things, i carry my XD40. I use each gun for different things, so IMO the guns are two different categories.
If you want a strictly EDC SD gun for close-in protection and easily concealable, go with the LC9. Don't plan on having too much fun target shooting though, its more practice to stay consistent with the trigger than it is fun, especially since recoil is just about the same as my XD40 since it's so small and light. Also, you only have 8 rounds (9 if you do the mag feeder modification), 7(or 8 with the mod) in the mag and one in the pipe.
The XD you have 11/13/14rds, depending on what mags you have (at least for the service model) so not only do you have harder hitting round, but you have more of them, and the gun is MUCH easier to shoot, it's fun at the range, and still small enough for EDC.
If i had to choose one or the other, it would be XD all the way. However the LC9 does fill some roles better than the XD40 does for me (for example mountain biking/carrying out to restaurants when i have my shirt tucked in, and long car drives it's more comfortable to have a smaller/lighter gun on you) and same with the XD, i don't really enjoy target shooting the LC9 like i do my XD. Maybe it's because of the nasty trigger pull, but that's next on my list of mods for my guns is fixing that trigger pull. So anyways i hope this helps, but IMO they are just a different category of gun. Different calibers, sizes, etc. The LC9 is more in line with the kel-tecs (which i hate BTW) and the little Kahrs, etc. The XD IMO is just a larger size gun and is more comparable to so many others i don't wanna start, but yeah just two different animals IMO. I do have to say though, i do like both of them and wouldn't want to give either up, but if it came down to it the XD is more accurate, more rounds, bigger rounds, more mod friendly, easier to shoot, better trigger, and fun to shoot at the range for more than 50 rounds
Or, you can be like me and get both! Problem solved!