I have the Sport EX touch screen and I've basically never used it outside of checking to see if it works. I'm day vfr only - perhaps there is something that you might need it for that I never use, so probably best to let the GRT guys convince you. The knobs and buttons work great, are well-designed, and have good tactile feedback.
The option I didn't buy - which I didn't even know was not included until much later - is the vertical software. Now I'm kind of struggling to plunk down $400 for it.