Sure, it is just software, that is true (still waiting for confirmation on the existence of double burn-in!!!), but the effect is real - people pay for software! Everyone is different, but to me the P3D- seems like the limited edition more practical (for now) car to have:
-Track mode added unexpectedly (bonus!)
-Efficient
-Versatile tires, cheaper replacements
-Very good brakes (though not trackable)
-Fits wide range of aftermarket wheels
-Better ground clearance than P3D+
The only thing that would make it bad/less desirable in future would be if Tesla boosts the AWD performance (which I doubt they will, but...)
Personally if the track mode had been available at my order time I would have gone with P3D-, and I would have been mostly ok getting the 5k back, and a little sad about giving up FUSC. As it is, I have a P3D+ on order and have to decide between FUSC and a true 5k discount. And the P3D- doesn’t exist, so I can’t switch to it even though I’d like to, since it would be 10k less than my original order price.
As far as overpriced...notwithstanding generally obscene Tesla prices, it seems P3D- was well positioned in the price lineup after accounting for the 5k (not counting sales tax impact) discount. We can argue about the value of the software but I imagine it depends on the person.