No cup shocks and springs are around 10% stiffer and a few mm lower. But as the chassis are the same you can use either. Though I won't be paying renos new price for the rear cup shocks if mind go there nearly 400quid each! Now.
My rears are leaking and I didn't fancy paying £600 for a new set of cups. I was considering fitting 182 shocks but got a new set of 133 bilsteins for the rear, haven't fit them yet though so can't comment on how the handling in affected.
It be just the same as cup, Bilsteins are buget setup and the rear are not coil overs so its all a bit sloppy and not suited to track day or anything to hard. Street it be just fine. Track suspension is crap on the road anyway. So your made the correct choice.
I know this as we use Ohlins and if we do some hill climbs we nearly get better results from cup's. We loose so much time making adjustment were as the cups we just have to drive around the limits.