No, it is tolerable if you don't know any better. That's like saying a gremlin is fantastic for 90% of what you'd ever think to use it for. If you have a choice, and know other cars exist, then you wouldn't think to use it for anything. If you don't know other cars exist, then you can hardly be believed for claiming it is "fantastic". Mysql is a nightmare. It is incredibly crippled, full of limitations that force you to add complexity to your code to work around them, and offers nothing positive to make up for these downsides.
>but both will get you a very long ways before they are ever your main problem as a startup.
Haha, tell that to our SQL server guy who got stuck doing a PHP/mysql project. He didn't get through the first day without coming to me asking "how do you linux people function when your database can't do anything?". He ran into three separate mysql limitations in the first day he was using it.