Of course, like everything else, if you spend enough you can go down 1000's of feet.
The biggest problem with poly is pulling it out, not so bad on a shallow well, but a major PITA if its a deeper one. Its all one piece, try to coil that shit up and not kink it. If you are replacing it, just saw it off, but if it hasn't been down there too long and you have a problem, you dont want to have to replace it, as its not cheap. You also have to be real careful pulling it, as its slippery. The good things are its one piece, so no joints, just feed it off a roll down. There is also less friction pumping, so a little more pressure.