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Lets use the two that you have listed. Aeromed, and Legal. I know the Aeromed is worth it weight in gold and anyone that has ever used them or had their careers saved by this group of people will swear by them. For DAL to retain a service like that, that is all about us pilots and our best interest will not be cheap. As for the attorney's, some are good some are not. I have meet a few of our attorneys that spend their entire lives devoted to things like defending "Chain of Custody" of our void samples. Do you really think that if we paid for that attorney and all of the others ones we employ that 1.95% of your paycheck would cover it? Doubt it, plus it would end up being some farmed out service provider that does not give the same level you now enjoy.
I have worked with other pilots that are non-alpa and trust me you do not know what you have.
Gonna go out on a limb. Tentatively. I'll have a definite answer in 24hrs. SWAPa, and some of the others at CAPA use ALPA aeromedical. They contract out their services. ( Side note: ALPA aeromedical is just a tad over rated any way. Dr. Tom Faulkner is THE MAN though. Got an issue, Google him, or just ask your base CP.)
As I see it the MCF is there is we need it. It is the threat of it that is the biggest deterrent. Have we gone on strike? If we do do you think that DPA can support us long term? I highly doubt it. That MCF will be there if we need it.
Ever consider that this is also a liability that prevents National from doing "hard" or "right" thing at times. Don't you think that the ATA or any of their member airlines would love to get their hands on that via a judgement?
So answer your question, what are the benefit that ALPA has or a new relatively unknown association?
1) Name recognition: The power base knows the name and the number that go with it
Home | Coalition of Airline Pilots Associations
3) Numbers. There is always a fear in the fact that ALPA represents over 55K pilots.
see above
4) Legal Support for you the line pilot when you get in trouble. Get in trouble and you will swear by them.
Really? If you were a good lawyer, do you choose a career with ALPA? I don't think they are any match for the companies law firm. BK proved that.
5) Aeromed; Again worth its weight in gold. Have a heart attack and do not have the influence that ALPA has at the FAA and you may be SOL with getting an SI. Trust me this is very important to all of us no just the old farts
see above
6) MCF: Lots of money. It sill there is one needs it. There are commitments to the MCF, but to date there is still plenty in there if we need it.
They earn a lot of short term interest on that 
7) The rest of the ALPA pilots would more than likely support us with a assessment if it ever came to it, with DPA you will have to asses yourself. Never been tested here, but ask the NWA brethren about this.
Again, really? Lets say that UAL/CAL leaves as well. Would the remaining group have the $$$ power or will power to do that?