Yeah, I kinda ran into the same issue when I tried running a Hurst T-handle shifter on mine. Part of it is the Steeda Tri-Axe shaft coming up from the shifter base being so straight, so it's not very ergonomic - shifting into 5th gear is kind of a reach, you've gotta lean over to get at it. Plus, as mentioned above, I like to change my grip on the knob for different gears. Going from 1st to 2nd or 3rd to 4th, I grab it from the top and pull down; going from 2nd to 3rd or 3rd to 5th, I have more of a pistol-type grip on it from behind.
Additionally, the damned thing kept coming lose, no matter how well I secured the jam nut and had the threads coated with Loctite. Few things make you feel dumber than having the handle spin on you when I go to jam it into 3rd gear and you accidentally punch the console, skinning your knuckles - I gave mine away the very next day.
The only way I see a pistol-grip type of shifter being practical in a Fox is if you have a very adjustible shift handle coming from the base - UPR has one that can be rotated for angle, as well as adjusted for height - and if the pistol grip knob, itself, doesn't have a squared shape to it like the Hurst style ones. Again, UPR has a kinda nifty billet aluminum knob that can be threaded on as either a T-handle OR as a pistol-grip knob ... but then you have the usual issues that you would with any all-aluminum knob in that it's hella-hot in summer and ice-cold in winter. (Just slip a sock over it, I guess.)
I'll stick with my leather-wrapped reincarnation of the stock Fox knob. No temperature issues, it's lightweight, and I can grab it comfortably from just about any direction that I want. Only thing better would be if someone would come out with a Bullitt-styled knob cast in a heat-/cold-resistant composite material. (Even the pool cue/8-ball knobs get kinda hot, and they're a bit too fat and too heavy for my tastes.)