Depends on what you are looking for and to do. If you want the most advanced tech stuff to impress, the aftermarket ECU might fit the bill. If you want simplicity, low-cost and retain all OEM features, stick with stock.
I had a reseller of the aftermarket ECU spend much of my valuable time at a recent auto cross trying to sell me on why I need an aftermarket ECU. I personally didn't see the need for it when I already have what I needed. Which that being said, there are certainly a time and place for the aftermarket units. Kaleb works with a Motech at school all the time on their SAE car, they NEED it. If you have to have sensors, data, and customization that's not available on the OEM unit, aftermarket is the way to go. But I see no reason to go that route unless your requirements aren't met already.
