I've never used Live Aquaria (although I use Drs Foster and Smith all the time) but I have heard nothing but good about them. They have a 14 day guarantee, and from other users here I have heard that if you do have to use it it is really hassle-free.
I have had many fish shipped to me, mostly from members here and aquabid, and I have so far only had one DOA out of at least 25 fish. It isn't as scary as it sounds. Just be sure to be home when the package arrives and be prepared to start acclimating the fish very soon after you open the box.