Hey Zach,
G-Skill is awesome. A great way to check brands is to look at customer reviews at Newegg.com.
Click this link and just scroll through every page -
Newegg.com - Computer Parts, PC Components, Laptop Computers, Digital Cameras and more!
With the exception of 3 of their varieties of memory, they have a 4 or 5 star rating on everything else and lots and lots of reviews.
As far as not playing nicely with other memory, it is usually voltage/timings that cause that to happen. And yes you are right, it is common, and unless you have a motherboard that lets you set timings/voltage, you just gotta dump the old stuff.
Hope that helps!
