My band uses Cubase and we have our entire set programmed in with click-tempo changes and backtracks. Of course, this is not a free option, but it performs phenomenally. Some people won't agree, but it works for what we are going for. We have one big track and we know the exact length of the set list which we rehearse to. So, we are familiar with the breaks between the tracks, the track order and we never have tempo issues.
To sum up, we use a laptop with Cubase, which is connected to a Presonus 1818, which is connected to an A+H MixWizard 12M. We only need to hit the space bar once!
My band: Windy City Slaughter (check it out on Facebook, bandcamp, soundcloud, etc. etc.)