I have had two cars with boxes and this current one remapped. One box was so called "quality" box and one el-cheapo. Actually the cheapo was better.
With this knowledge I now have I would go for remap. Save a little longer and a remap definately.
The quality box made my Jetta TDI PowerDiesel not very nice to drive. Very hasty, how do you say it... The cheapo was better, but did not deliver what it was supposed to. Not as much power.