First of all, in listing the current first and second tier QBs that Newton might one day displace, Brandt did not mention P. Manning or Brees. Those guys are going into the HOF. If age were a factor in thinking these guys will roll into retirement opening an "elite" (or second tier spot if others "move up"), why did he mention Brady? The whole thing is was quite peculiar.
As for the question of whether Newton is worth this kind of money, it's pointless to compare his contract to those of QBs with superior credentials. The question to be asked is, "what are Carolina's options if Newton goes FA to another team?" Further, the teams muddling with the QB position are inclined to sign him for the same or more money for the same reason.
There is a problem for the NFL that simply does not get enough attention, one I've mentioned before...colleges are not producing NFL QBs. Name the current first or second tier QBs (or even high 3rd. tier) QBs who are under the age of 30.
There's Luck. Then there's Wilson (more about him in a bit). Then uh, uh, uh. And the further along we've gone in the last decade, the worse it's gotten, as the number of college teams running spread/option schemes have proliferated, traditional NFL QB skills are compromised in the process of valuing QB running ability.
That makes sense in the college game where the QBs play for a year or two and are gone. This spread/option stuff is easier to teach than reading defenses pre-snap and reading route progressions, not to mention NFL mechanics. The NFL is not keen on jumping on the college bandwagon; spending a high pick on a running QB with some arm strength (and then paying him a franchise-type second contract if he survives unscathed) is a risky proposition (see RGIII).
So, Carolina takes the risk anyway..for lack of options. I suspect others will be forced to follow...by either embracing the college scheme a la Seattle (with Wilson teeing up for a franchise contract) or just paying up for a QB like Newton who makes hay breaking the pocket even if his passing skills leave something to be desired.
Will Newton be a top 5 QB before this contract is up? Why not? Who else is there coming through the pipeline? The bar will be much lower when these current first and second tier QBs start rolling into retirement.
It's beginning to look like we're nearing the close of the golden age of QBs in the pass-first era. Rodgers will be the undisputed top dog as the three future HOFers retire. Second tier guys like Roethlisberger (who may get in the Hall himself), E. Manning, Rivers and Palmer are getting up in years.
Will Newton be contending with Wilson, Matt Ryan, Joe Flacco and Matt Stafford for "seasoned elite" status. Maybe Ryan Tannehill gets thrown into the mix. How about Kaepernick (forming the "option/running QB elite" with Wilson and Newton) as SF evidently intends to go back to a heavier dose of option snaps?
When the bar is lowered for what qualifies for elite quarterbacking, the door is certainly open for a guy like Newton.
