I have the Billetworkz short throw shifter on as well, but I won’t go into details on the shifter until I make a review on that.
I originally had on the 2 inch extender on and that felt pretty good. However, I thought what the hell, there’s a sale on accessories and I’ll try the 4 inch. It felt pretty big and the hand placement took some getting used to, but I felt like the extra extra long handle has made my transmission shift just a liiiiiiittle better over the 2 inch (transmission issues from the start when I got it). I feel like I can shift better from 4th to 5th with the 4 inch on than the 2 inch and WAY better over no extender at all. It still makes me giggle from time-to-time when I see its glory in the sun and how ridiculous it probably looks, but it definitely has wow factor for sure.
I will say you should have a small crescent wrench in your glovebox with some painter’s tape on there to tighten it down just a little more when you need to. Maybe I wasn’t tightening it on tight enough, but I felt like it was coming loose a little bit. I got it to wear it wasn’t wiggling loose. No big deal.
In summary: Great given you have the short throw shifter on.