Nick, nothing wrong with the older Ribtecs, but they recently taken over by Ribeye, not sure about any later hulls built in SA though. Since then the Ribtec brand has gone quiet and Ribcraft seem to have taken the initative during the last 4 years. The smaller 5.35 was based on an early Watercraft mould (same as the Solent 5.4m). The 5.5m Freeway is a medium v hull, and for buzzing around the solent probably well suited if you can live with the driving position and bench seat layout. From 585 upwards they are all deep v hulls and well made. However just like BMW during the 90s you were paying a premium for the name. They do need lots of power though to make them move, one downside to the deep V hull. The 6.45m hulls had a habit of gelcoat cracking along the shines as the outer hull flexed but they still go on for years like that.
6m hulls are rare, there was a 6m hull with a Volvo diesel stern drive (105 hp) built about 96 time which was very frugal. Take a tape measure with you to see if its a real 6m or a 585. Alan Priddy reconned the 585 one of the nicest boats around and I agree with him. They are very soft landing and an ideal all round rib size. Jimbo has one on here, and there were some photos in the gallery of his, It must be 10 years old and having been used as a dive boat shows the original construction was good and the previous owner looked after her well. Now if he would just sell it too me because he needs a bigger faster boat we would all be happy
. If you want lots of different opinions of one particular boat, post the details, but for UK built boats, one of the better builders IMHO,