They are completely different animals. The Searider is a deep V sea going rib, where as the Higfield is much more leisure orientated, The Highfield takes a short shaft engine and means the hull is much flatter.
I really like the Highfield, but it needs to be considered more like a very competent sib, rather than a seagoing rib. The Highfield can also be used quite happily with a tiller set up, this gives a lot more space on the deck compared to a Searider with a jockey set up.
IMHO, both are really good boats, but totally different to each other.