BU: aaron d summed it up.
there is a feasible limit, as well as feasible set of flight paths discs will do.
the discs i push are ones that CAN be forced to do a billion things.
you aren't going to practice turnover rollers with a 180g ram if you want your shoulder/elbow to maintain its nerve endings and connective tissues intact.
similarly, good luck learning to throw a distance anhyzer with an optimizer.
discs can be "best" measured upon the best characteristics for said flight path. "best" straight driver = disc that has the greatest resistance to high speed turn, least amount of low speed fade, ease of throwing and best carry with the stability factors in mind. clear cut winner = dx teebird. there isn't another disc out there that is as high speed stable, with that little low speed fade, and carries that far while being throwable by someone w/ 225'+ power.
discs that become flippy for players throwing under 400' get beaten out. discs that are too overstable for players throwing under 400' get beaten out. in reality, there's only a handful of discs that can even moderately rival the teebird's flight characteristics: dx gazelle, dx teebird, e sabre, z xl, q jls, star tl, champ leopard, x cyclone, etc.
basically, the teebird is in the upper 1/3 in minimal fade (especially if broken in a bit), the top when it comes to high speed stability, and the top out of these discs when it comes to distance.
on an additional note, if you include the upper eschelon of drivers, they all pretty much get eliminated since they fade a LOT more than a dx teebird ever well.