First pic shows my rib alongside woot's rib - mine is a Destroyer 6m, and woot's rib is an Assault 5m from what I recall. From the pic, you can see the beam difference, and also an increase in depth in the deep v configuration on the destroyer hull. The Destroyer also has a higher cut bow than the Assault, and the Assault in chop will get the cox and crew quite damp
Thus far, I have not managed to get any water over the bow on my boat - if there's a side on wind, the engine gets wet at the back due to spray coming over the side, but that's about all.
We have 4.9m assaults at the yacht club, which are great fun, but when conditions get rough, they like to point into the sky even with the engine tight in at the back..... if you ballast down the front end, the water just comes neatly over the bow
The next pic shows the Assaults alongside a 9m Ocean Pro - you can see the bow height difference here - the Ocean Pro is a very different boat altogether, as Dave said with more spray rails.
Even with crew on board, and with chop around, this ocean pro doesn't get much water on board at the bow at all.
I think if you tell Humber what you want to do with your rib, like where to use it etc... they will come up with a suitable craft for you.
My decision was based on previous knowledge of using a Destroyer (7m with 200hp Johnson V6) which I have to say was an amazing craft - very softin chop and at sea..... this is what I did my level 2 on many years ago, and it felt very solid/stable.
If I had thought about it more, and had more money at the time, I may have gone for the Ocean Pro, cos it's beamier than the Destroyer for the same length, and has a very high bow which makes you feel very secure behind.