What you find to be optimal doesn't necessarily equal what can also be just plain useful is what I'm saying.
Whether you play two games or 6 in coop (which is the typical number to get to 5 with just a stimpack and no extra bonus), you are learning a great deal.
What is the range of 'x' ability? How long is the cooldown? How does the passive work? What talents do they have available? Why does this ultimate seem so annoying?
Even a rudimentary effort with two games lets you see a ton of this stuff and is ridiculously useful in a game setting against that hero versus going in blind.
EDIT: I'm just trying to help. You seem to be regularly frustrated to the extreme with losing or the quality of your games. These few things are the easiest ways to overcome that (play heroes that counter the free week, level each hero to 5 to learn them, etc). Sticking with one hero all the way through to 10 indeed teaches you a ton about a hero. But if you do that to the exclusion of all else, you're gonna lose more unless the hero is inherently strong and you're missing out on any other hero who is available to give it a test spin.
I come from FGC, and I've played competitive gaming a long time so I know exactly what you mean. I'm not denying the fact that you can learn the utmost basic stuff (cooldowns, range, etc) by playing a few games with that individual hero. I am however saying that that is something you
also learn by playing against that particular hero as well. I haven't played Thrall for one single game, but I know the approximate cooldown of every spell he has, the range of his wolf-cc, the usual timing on his earth-Ultimate, etc. That is knowledge I gain by just playing a helluva ton games.
I mean, when a new fighting game came out back in the days when I was into that - I couldn't possibly play every fighter in the roster "just to learn their combos". That would've taken me way, way, way too long time. You simply play the game, and eventually, if you have the competitive info-absorbing mind set and awareness, you'll learn everything there is to know.
I also don't see how I am being "regularly frustrated to the extreme". Today, I was frustrated at the experience cap and not complaining about some hero being overpowered and whatnot. I don't even remember when I made such a post last time. Yah, I complain on Mumble but it's been at least a few days since I was complaining reaaaaaaally hard about a hero in this thread. So I don't get your "edit"-part at all :/
I'd say he's right. After 5 or 6 games you may have a fairly solid grasp on the characters abilities and a build that works but it takes quite a bit longer to actually master a character.
Yup. I'm level 5 with Johanna (because of the silly warrior-dailies) and I have learned
literally zero things throughout these games. Every knowledge I know about Johanna came from playing against her (which I've undoubtedly done over 150+ matches now).