The unit is 5 1/2 years old and has started skipping over bumps and then generally loosing the plot and not tracking. Actual sound quality is fine when it's working (through an Alpine amp and Infinity speakers)

Is it worth having it repaired or just bin it and get a new one?

 

If it's an ODR unit, it's worth repairing. Other than that, have a look at what new top end pioneer stuff is going for (excluding the P90!) and make your mind up. The top of the range head unit/mp3 player looks tempting to me...