I never said it doesn't have its uses. Just noting that if the wired option exists, it is definitely better as far as transfer rates go.
Well with the 200Mb/s adatpers, they definitely are slower than a Gigabit ethernet connection. However, now that there are Gigabit versions, I wonder how much of a difference there really is. Yes, they will still be slower, especially if you are running them over multiple circuits, but the speed should still be pretty fast.
DO NOT PLUG THEM INTO SURGE PROTECTORS! This is usually burried somewhere in the manual, but it should always be there. The way surge protectors work
can cause the adapters to have extremely bad speeds. With my 200Mb/s kit, when I accidently plugged one into a surge protector my speeds were below 1Mb/s(Yes, bit not byte). Moving it directly to an outlet fixed the speeds. I believe it is usually the cheaper surge protectors that cause this problem.
I haven't had any problems with GFCI outlets or circuits causing problems, though we only have those in the bathrooms and kitchen, so I really don't have a need to plug the adapter directly into them.
One of the advantages of these over wireless, besides the speed, is that it is easy to plug multiple devices into one unit. The main reason I got mine was so that I could run one from my basement where my router is to my living room where my TV/Xbox/PS3/Media PC was located. I had to plug the Xbox, PS3, and Media PC all into it. So a simple 5-port switch was all I needed to get all of them running with a wired connection. No need to buy a wireless adapter for the Xbox or Media PC, so it kind of paid for itself.