Definitely worth fitting one.... I had to have my 8 in the garage twice (to replace the sump plate once and the plug twice). And neither hits were hard.
But consider the plate as a 'rubbing plate' rather than something that makes your sump bullet proof. When you know there's a major or sharp hump, proceed over with great caution and you'll feel the plate making contact.
Bell & Colvill fitted mine as I didn't fancy tackling it without a full lift.
