I had one, and just sold it on this forum as I sold my Big Stopper and have moved to electronic long exposures.
Its very well made, and works well, but not at wide angle.
Even collapsed I did find it vignetted a little at 24mm despite having also been assured by Lee that it wouldnt.
Its not much and really not a big problem, but sorta defeats the purpose.
So, from my own experience if you are shooting at say 40-50mm and above then it will be absolutely fine, if below that then the extra for the wide angle hood is probably money well spent.