Yep, 50 should be no problem for you. I finally hit the magic number about a wk ago. I had constantly been gettin 48-49kts. Last Saturday I went for it and trimmed her up to about 3.0 on the Opti gauge. Revs rose from 5250 to 5500 and wahey!! 50kts
(running a very light boat though)
Its not so much the speed that will impress you about the boat though, the cornering and the ride in the rough are far more impressive than the speed. I nearly threw 3 of my crew overboard last wkend. I don't think they realised how sharp she could turn at 40 kts
Its not a fast hull like the Solent's, its basically the Tornado high lift, hull design, but built by a major UK manufacturer. The lines are similar to the Solents but the angles, etc. are deeper. More of a rough weather boat than out and out speed so you should get 50 but not much more after that.
Sorry about the diversion back to Optimaxes!!