So I'm pretty sold on the Pioneer, my question is which one? I have a minivan, don't care about really earth shattering sound (occasional loud). Just crisp clear sound at reasonable levels. No Ipod yet but may in the near future. Mostly listen to rock and talk radio, like the idea of just plugging in a USB flash drive. Wanting to spend max ~$300-$325. Would you recommend the: 790BT, 780MP, 880, 690UB ???