Personally, having tried all available benzos, I prefer Valium - at the correct dose.
4 mg of valium a day is truly laughable, that dose is insignificant, you may as well be taking nothing.
I take 10 mg of valium x3 a day to control GAD. Valium is my preferred benzo because it does last seemingly forever and it kicks in as fast as xanax if needed for a panic attack. Because I take it daily I'm sure that the levels of it in my blood pretty much remain constant. So I often forget to take it with no ill effects when I am not anxious and I don't get any of that inter-dose withdrawal.
Personally I hate ativan. It does nothing to relieve anxiety for me, it just makes me tired. In the past I have taken 40 mg of it, still felt panic and eventually just took a nap.
Everyone is different though. But to give Valium a real try, you're going to need more than 4 mg/day.
Over time though, I feel that being on valium daily has slightly increased depression for me after a couple years. But It's been the best solution for me.