I loved Valium when I first took it. Can't describe the effects but something similar to Soma (probably because it's also a minor muscle relaxant). I hate Xanax, and if I liked it, I probably would hate the duration. It was pretty much just a sleeping pill for me and the couple times that I did take it, it made perfect sense that it was an anti-anxiety EPISODE drug, because that's probably where its effect comes in the most handy. Valium however was very enjoyable for me, the most out of any of the traditional benzos.
Had some 5 and then 10 mg tablets. Would take a variable amount and just feel numb and slightly contented. The perfect drug to take if you're having one of those days where you just want to lay around and watch the Back to the Future trilogy or something (which is what I did).
However, I can't recommend Valium (or any other benzo) at all because the amount of time that the working effect really lasts is SO short. After three weeks I found myself angry that the dose I was taking was doing almost nothing that it was doing just 15 days ago.
So while taking 30mgs again isn't going to hurt you, you probably should stop after that. Benzos give you the absolute worst whiplash if you become even just a little dependent on them - like potentially a withdrawal that lasts 10x as long as however long you took them. When I say "stop", I mean with the Xanax too...any benzo, if you've only taken them a handful of times.
Also, never mix benzos with alcohol. Ever. Especially since 20-30mgs is going to be a lot for someone who has only taken benzos a few times. Wait until you can't feel the Valium anymore, then wait like an hour after that, then you can drink.
Be safe man. Benzos are the worst if you get stuck on them.