Long waits for care, like waiting months for appointments, and can be very difficult to reschedule. Substandard care is pretty common. They try to cut costs and don't pay very well. They even have looser restrictions on physician testing than states, so sometimes you end up with lower quality people that couldn't hack it under the state requirements. Oftentimes you're seeing a PA or nurse practitioner rather than a physician. For basic things that could be ok, but usually the people in need of care at the VA have complex needs. Long waits for approval of benefits which can take years, require multiple applications as they almost blanket deny some claims, and sometimes require legal assistance with third party medical evaluations. Limited facilities means long drives for some people, and even makes it a near impossibility for some.

I honestly haven't heard anything good about the VA other than it's free (but was really earned through service). The good care tends to be at what I would call the active duty facilities, like Walter Reed and Bethesda.