MEL to CBR on a Rex Saab. Lovely day, smooth flight for most of the way but after coming across the range before descending into CBR we hit what I assume where thermals, and just dropped as well and there was a bit of rotational movement as well, one wing went one way, the other a different way. After that initial shock, all pax white knuckled the aircraft stablised but it was pretty much like that (albeit less severe) all the way in. As disembarking, overheard the FA talking to the pilot "do we have to go back through that again ..."