Before Blockbuster went into bankruptcy, their service was equal to Netflix. I live in a city that has distribution centers for both and was a customer of both at different times. If our at home queue was empty on Monday and a new release was getting released on Tuesday, both services would mail the DVD on Monday and you got it in the mail on Tuesday. When returning a title, both services would get it the day after it was mailed back. When Netfix started the 28 day wait for some new releases, Blockbuster got the edge over Netflix, at least in my mind.
When Blockbuster went into Bankruptcy, their service got real bad so I went back to Netflix. After Dish bought Blockbuster, the service got better and after trying it out for free, I left Netflix and went back to them. Service was a little slower but they still mailed new releases out on a Monday so you got them the day they were available in the stores. If a movie in your queue went into a wait state, I noticed that the wait was longer then in the good old days, and it took longer for a mailed title to get to you because it usually came from a different distribution center.
Since Dish started offering their BBMP plan, service in the Phoenix area got really bad. I wouldn't get anything sent to me, things would fall in the the long wait black hole, they would send me titles that were removed from my queue when I checked it out at a store, and the one that caused me to drop Blockbuster was not getting any titles for over a week.
Short of getting the service free for a year, I'll stick with Netflix.