I've never tried Flexeral. I wanted to try Soma as it's metabolized into meprobamate, which was a wildly popular tranquilizer back in the 1950s. The reason I wanted to try meprobamate was because I have disabling anxiety which benzos entirely fail to control.
Back in 2003 I started on Valium 40 mg/day and that did nothing. My GP wan't brave enough to go higher than that so I found a psychiatrist who absolutely loved benzos. He put me on 10 mg of Xanax daily (equal to 100 mg Valium) from 2003 to 2012. Even that dose didn't really do anything, though I kept taking it as I hoped it did at least a little something. All Xanax did was kill my sex drive (back when I actually had one -- I don't any more despite years off benzos). In an effort to see if Xanax does anything at any dose I once tried 120 mg in a single dose. I don't recall if it actually calmed me any, but I got a 5 hour nap from which I awoke feeling the same as usual. I've also tried Ativan, Klonopin, Onfi (bet you never heard of that one), clonazolam and a number of other research chemical benzos.
Since this is a suicide forum, I probably need to point out that 120 mg Xanax was not some half-assed suicide attempt. I am fully aware that the LD50 is something ridiculously high like 900 mg/kg in rats such that you'd need many thousands of bars to produce death. It's so exceptionally unlikely that I'm not even aware of a single documented case of death by Xanax alone, though it certainly does pop up often enough in deaths (with a pharmacy of other drugs, especially alcohol & opioids).