One month has passed and now it's time to publish the results. There were 47 voters this time and the results can be seen below:
YES, and i'm still stuck with it 9 (19%)
YES, but i have solved it now 18 (38%)
NO, it worked like charm out of the box 8 (17%)
NO, because i don't use NVidia card 12 (25%)
Looks like the Nouveau problem are no longer a threat for most of Linux users, specially Slackware even though it's still not as stable as nv or NVidia binary driver. Only 9 people who had problems with Nouveau, while the rest is no longer having problem with it.
I hope this problem will be solved during the next Slackware version get released