We had some issues playing. One of us even had to return the game.
In his case, it legit did not work. At all. He has the same specs for his computer as me, but it took 20 actual minutes for the game to finish the opening cutscene.
After that, those of us who COULD play the game found that fighting things solo now took around 40m of styling all over a monster until it eventually died. I had one who was limping for a full 10 minutes while I comboed my T11 insect glaive on it's face. So basically we unlock the monster cutscene and band together to fight it each time, and we're having fun again.
That really sucks with the gamebreaking bugs. I sincerely hope Capcom gets their butts in gear quickly and figure it out; even though the game hasn't presented a problem for me, I know what a draining experience it is to try and work out issues with something that shouldn't have issues to begin with.
I'm surprised to hear how long the fights are taking. I'm not entirely sure what you mean when you say T11--does that mean Rare 11? Because if it doesn't and you're still using a weapon from High Rank, replace it with another weapon made from Master Rank materials immediately. High Rank weapons, even the top-tier ones, will do something like 40% (extreme guesstimating) less damage on average than the simplest weapon you can acquire in Master Rank.
After grabbing the basic ore-crafted Master Rank hunting horn, most of my hunts, both alone and with one friend, have lasted around 15 minutes, which is pretty average for starting Master Rank in Monster Hunter. 40 minutes is a heck of a lengthy period, and the game by no means expects your every hunt to take that long.