Thus far, it seems to be benefitting quarterbacks the most.

I've actually thought about this a fair deal over the past several months. I'm not sure if it's what you say, or if it's merely that teams are getting burned too often by huge FA signings and are learning from that. The timing is coincidental, but I think it's more the latter than the former. GMs and scouts see Arizona pissing away a ton of money on Kolb, the Eagles with Nnamdi, the Bills not getting equivalent/expected production from Mario, etc.

Here's the thing though: Teams have been doing that for decades. Why are they suddenly now learning from that? I don't think the timing is coincidental. I think that the situation has changed. Before, to get that elite guy, you either paid big bucks in FA or you paid big bucks on an unknown risk in the draft. Now, teams can take a risk in the draft so they have options. Before, it was pay the guy big bucks or pay an unknown rookie big bucks and take your chances.
It's driving down salaries having a cheap labor pool.

Actually it's more a case of the rookie salary cap giving teams room and leverage to resign their own guys, you'll find a lot more with players now that there won't actually be that many top-flight guys who hit the market. When they do, they'll still get paid (Mike Wallace, Mario Williams, Vincent Jackson, Peyton Manning etc).

Do you not think it speaks volumes when we picked up two of the "top 5" free agents in Bennett and Avril, yet neither are among the top 10 at their position (arguably, of course)

The thing to watch for is how ownership tries to wrangle the extra cap money in roll over spending as to make it look good but be cheap like the Bengals have always been.

Section 9. Minimum Team Cash Spending:
(a) For each of the following four-League Year periods, 2013–2016 and
2017–2020, there shall be a guaranteed Minimum Team Cash Spending of 89% of the
Salary Caps for such periods (e.g., if the Salary Caps for the 2013–16 and 2017–2020 are
$100, 120, 130, and 150 million, respectively, each Club shall have a Minimum Team
Cash Spending for that period of $445 million (89% of $500 million))
(b) Any shortfall in the Minimum Team Cash Spending at the end of a
League Year in which it is applicable (i.e., the 2016 and 2020 League Years) shall be paid,
on or before the next September 15, by the Team having such shortfall, directly to the
players who were on such a Team’s roster at any time during the applicable seasons,
pursuant to the reasonable allocation instructions of the NFLPA.85
(c) Nothing contained herein shall preclude a Team from having Cash
Spending in excess of the Minimum Team Cash Spending, provided that the Team complies with the accounting rules of the Salary Cap set forth in Article 13.
(d) If the NFL agrees, or a final judgment or award is entered by the System
Arbitrator, that a Team has failed by the end of an applicable League Year to make the
payments required to satisfy a Team’s obligations to pay the Minimum Team Cash
Spending required by this Agreement, then, in the event the Team fails promptly to
comply with such agreement, judgment or award, the NFL shall make such payment on
behalf of that Team (such funds to be paid as salary directly to the players on such Team
at the direction of and pursuant to the reasonable allocations of the NFLPA).

Each team can only afford a few premium deals, and the top QBs are taking up more and more of the available space. There's just going to be high quality vets who are underpaid. In a few years when RW is making $20+M/yr we're not going to be able to afford a TE with a cap slot of $11M. Our roster will begin to look a lot different.

The Bengals are REALLY screwed. They dont even try to coerce FA's from outside, there's no point. They sign their own Stockholm-ed players, exclusively.