I only know about flight attendants (because I was one and still have many friends there) and pilots because I'm dating one. From what I understand, the PMNW F/A's will be getting higher hourly rates, but many benefits will be inferior, depending on who you talk to. The problem with benefits is that their importance is somewhat subjective-what is important to one person may not mean diddly to another. I would think the A Days program would be a step up. When I shared an apartment in Queens with 4 PMNW (before the merger) they were all on reserve with 10+ years-and hated it. I'm sure there are those who like being on reserve (I never did).
DL actually puts in 2% to your 401k regardless of whether you contribute and will match an additional 5% dollar-for dollar (my current employer, one of the best hospitals in the country, according to US News & World Report) does not. In fact, our company match is less than DL all around. We also work 12.5 hours. I didn't even know there were people out there getting a paid lunch. I would hate to lose that too.
PMNW topped out at 14 years; DL tops out at 12. PMNW will see higher pay in basic pay scales, LOD program, Per Diem, Purser pay, Domestic flight leader pay, profit sharing, and shared rewards (which is anywhere from $400/2010 to $875/2007 depending on performance metrics), and will lose the extra pay when no bunk/crew rest seat available.
PMNW will lose sick time in a big way. DL F/A sick time is a joke (IMHO). 42 hours per year is simply not enough for the F/A position. 2 3-day trips and you're pretty much out.
Retiree medical is inferior at DL. STD and LTD are provided, with an option to "buy up" (which is common at many employers).
So, trying to be as impartial as possible, you can see there will be gains and there will be losses. How much depends on who you ask and what is important to them.
FWIW, DL is replacing the Asian IFSR's with US-based LOD F/A's starting 01May2012. This is a good thing. The IFSR's will only be used on the intra-Asian flights. All flights to/from the US will be staffed 100% with US-based F/A's.