Yeah the diesel's perform well stock.

I've had a JBD (burger tunning) and it noticeably improves power especially over 3K rpms. It makes the car much more gasoline like where the power continues to rise as speed increases. You can buy one used for $100, best bang for the buck.

I have moved on to a JR Tunning Stage 2, with EGR block. I did this to stop CBU which is a major issue on these engines. I'm also tuning out various components now that my car is no longer under warranty as they fail. Some things maybe covered by various warranties and some aren't. But at somepoint the item will fail, and you can decide to fix it or tune it out. Its good to have options.