I have my home warranty through Fidelity and this is the company they always use to fix my plumbing issues. They are very responsive and call me right away to schedule a visit. Thankfully I haven't had any emergencies where I needed them ASAP, but they always seem to be able to come out the same or next day if needed.
The only bummer is that, like all services like this probably, the time windows in which they will come to you suck. Like HUGE blocks of time that you have to wait at home and basically ruins your entire day. They will however give you a call when they are on their way which I guess is better than nothing.
Anyway, all the plumbers who have come to my house are knowledgeable, friendly and do solid work. However, I can't comment on their prices because I just pay a small deductible to my home warranty company and they take care of it.
* Pro Tip - No matter what number you call to get Alan's Plumbing, 80% of the time you will get a busy signal. Just keep trying and eventually you will get through. It is frustrating but they always pickup and are almost always friendly.