Ribeye - Went out the summer before last in out Solent 6.5 with 3 Ribeyes a Shakespeare and another boat, I forget which, on a wee jaunt over to Alderney for the day. Great fun, but we had a good 3 knots on the Ribeyes with the same and more powerful engines than our 150 opti. Partly I'd atribute this to their tubes not touching the water and the fact they looked like they were rocking at high speeds. We had 6 adults on board, and theirs with 3 people upwards weren't keeping pace. The 6m Shakespeare was however, and I think they could have taken us. It was flat seas and I've heard better things about Ribeyes rough weather performance. Personally though I wouldn't.
Shakespeare - What I've seen and heard I've liked.
Revenger - They just look so cool, who cares if they perform!
Redbay - If you can afford one, go for it, the build quality is excellent and they are some of the best foul weather boats, however aesthetically they are lacking somewhat, so for a family boat, maybe not.
Scorpion - Awesome, looks the part does the tricks, but the price tags attached - mostly your paying for the name I think, but the quality of build, from what I've seen in their factory (shed) is really great, maybe biased though cos I get on with the guys there being local.
We too are considering the next step in terms of boat size, the 6.5 Solent wasn't so amusing in a force 7/8 on the way to Weymouth, and a little more length may meet our requirements, especially maintaining some sembelence of speed in big sharp seas. Of course a Scorpion would be great, so i'll start planning a bank robbery now... :S
This probably wasn't hugely helpful, but it's my observations about some of the boats discussed above.
Merry Xmas and a Happy New Year one and all