I will be open and honest in my belief that the Pacejka formulation is a convenient and thorough technology that clearly works for some tires. In fact, these tires are often designed and structurally configured to produce test data that conforms Pacejkally to the 3 regions of tire operation: Straight ahead ("linear range") driving on 2 or 3 lane roads at legal speeds and low bandwidth drivers. Then the midrange region with significant load transfer, softening cornering stiffness and significant second partial derivative changes to forces and moments due to slip, camber and vertical loads. Lastly is the region of operation seldom experienced by drivers still in control (or who believe they are in control) of the vehicle.
This is not a two way street. There are many tires with structure and tread materials which clearly do NOT fit the Pacejka paradigm either by design or by manufacture or by use. Work-arounds for this 'problem' include adjustment of the fitting algorithm's weighting function to downplay the area or poor representation. (You give up low g-level fidelity to get the best racing groove clarity). Or you give up the max-lat fidelity in order to meet a vehicle manufacturer's cornering coefficient specification. And of course there is the symmetry problem.
The 'best' data modeling in my experience comes from continuous splines that will clearly track all three regions and asymmetric characteristics. The weakness in them has to do with extrapolation and use conditioning factors (i.e. there is not practical way to adjust the splines for a change in air pressure or wheel rim width for example). The splines can be slow because of computational overhead and require large storage space in a tire library. You need to test every tire you use. No way to create clones of other tires because there is no structural basis for the coefficients produced. But if you have a good machine and a wisely chosen test procedure. You get data good enough to get a car successful right off the hauler, as they say. It's expensive to. You have to (or should) test every tire you use at each wheel position. Some of us have had the luxury of checking a box to get all this done, including the spare and also some non-sticker tires because the ones right out of the molds need to be cooked off in order to get stable results.
Let me also add that this whole thread also needs to have mention of a vehicle test program which is NOT related to track use or lap time generation. Instead, measuring control engineering parameters (gains and response times and natural frequencies and damping factors) for at a minimum of two conditions: Tires in a base position and also with fronts and rears switched. If the results are nearly the same, you can be pretty certain that you have a stable, consistent and manageable vehicle development program. If they are not, you probably have a 'flyer' at one position and so it is a waste of time to continue any further adjustments to the car (or truck, or golf cart or go-cart). This works well ever when the tires are different constructions on left and right sides.
I've looked at some other Hoosier non-TTC race and performance tire tests and am not surprised with what I've been reading here. They are not like globally available MacDonalds cheeseburgers all made from the same process book with identical ingredients, color, smell and taste. Since we usually tested three tires on of a given car for a model correlation comparison ( a front, a rear and a virgin extra), its nice to see a stable and consistent thin line for each tire (as I've shown in my previous rhetoric). But it isn't always the machinery, or the belt prep or the operator or the mounting and pressurization sequence. Sometimes its the Chef.