I must be the odd one out....
I have had nothing but good experiences with the VA, as did my father who died two years ago from injuries sustained in Viet Nam. He had few worries regarding his treatment (which undoubtedly extended his life by at least two to three years -- long enough to see his grandkids graduate high school).
That being said, the VA is a large bureaucracy, and you need to be prepared to walk into a process with them with patience, perseverance, and DOCUMENTATION, DOCUMENTATION, DOCUMENTATION.
They aren't just going to take your word for it.
I had a significant claim coming off active duty and most of it was recognized...not all, but most. The most important things were:
1) I took the time to do it.
2) I actually got a physical coming off Active Duty (you wouldn't believe how many people blow this completely free service off because they "just want to get out of here").
2) I kept good records when I was active, and had the records to backup my claims to include a complete copy of my entire medical record from active duty...dental too. The VA only considers claims on conditions incidental to service....you've got to be able to prove it. Your having a bad back at 40 is not good enough, just about every male over 40 has a bad back.
3) I consulted with advisers early and often, and listened to what they had to say (i.e. "the day of your physical do not take the Motrin").
4) I did not get emotional nor did I waste my time pursuing issues that were simply too difficult to substantiate. I will be blunt, most of us are aware that many people coming out of the first Gulf War had a variety of illnesses that are difficult to isolate---if you're pinning your hope on the vagarious of your health after serving in Shield/Storm...you're wasting intellectual and emotional capital.
5) I took the time to read the law and corresponding regulations regarding compensation claims and paid attention to the news.
6) I maintained copies of all correspondence.
Last month I strongly advised my father in law to return to the VA with documentation on his health issues. He had been out of the Navy for over 15 years and the last time he talked to anyone in the VA was the day he left the service. Imagine his suprise when he discovered the amount of additional compensation he was entitled to, and the various programs he had available to him now that were not available at the time he left the service.
He's also a packrat and has every scrap of paper the Navy ever gave him...so the documentation was resolved by just going through the mounds of paper.