Can someone just try it out and see to which group he belongs? I mean, was the benefit night and day for you once you got on the drug?
Yes and no; a huge component of tinnitus distress is often anxiety which can lead to muscle tension and pain. Klonopin will do something to help those problems in many cases, even if it doesn't do anything else to the tinnitus. Someone who feels less distressed may have a hard time explaining or even understanding exactly why.
How much of a volume reduction are we speaking? Could you make an estimate?
I can't because I don't think about it in those terms. Before I grudgingly went on this med cocktail I'd essentially spent 6 years thinking about tinnitus nearly 24/7, and somehow managing to jam my job and marriage and everything else into the periphery of it, and frequently broke down in fits of agonizing pain and depression.
Since I've been medicated I am aware of my tinnitus far less, I generally spend most of my days thinking about other things, but it will still creep into my consciousness, and any time I experience any kind of period of heavy stress, the bad tinnitus comes back, along with all my other anxiogenic symptoms (sweat across the brow, shaky hands, inability to think clearly, sense that the whole world is "hostile" and "dark"). I've also noticed a heavy correlation between the severity of my TMJD symptoms, and my tinnitus, and anxiety in general.
I don't want to be too glowy on benzos because I'd done the withdrawal from them twice, it's a nightmare, and because I was heavily involved in a benzo withdrawal community for a number of years, I know all kinds of horrifying anecdotes about benzo use leading to people's lives being upended or destroyed.
It's a difficult calculus, and my best advice, really, is "if you're about to eat a bullet, then maybe try a long acting benzo at a moderate dose for a while, maybe combined with Gabapentin". I think Gabapentin by itself was worthless to me, and I think these drugs overall are dangerous enough that this is unwise unless you're literally at that point of desperation.
It took me six or seven years of trying everything else under the sun, being a lab rat in two different tinnitus research studies, and ultimately probably spending $20,000 - $30,000 looking for other ideas and solutions before saying "sigh, alright, fuck it, give me the pills". I do not regret any of that time or expense because it led me to be pretty firmly convinced I'd tried everything else.
Benzos aren't magic for me, neither is Gabapentin. The combination seems to give me a higher quality of life for the moment.