The features I look for in a deck:
- Parametric EQ,
at least 5 bands, preferably 7. Helps to compensate for poor vehicle acoustics.
- HP/LP crossover with adjustable slope up to 24db/oct for each output
- High voltage pre-outs.
- Non-fading subwoofer output.
- Defeatable amp. No sense in having it running even with no load if using amps.
- iPod control.
- IR remote. I usually integrate the stock steering controls so they control the deck.
- Look purty.
At the time when I bought my deck, Alpine was the only one that fit these requirements.