To get back to the original question, I did extensive research last year before buying Topaz, which si a 6.2 Avon with Honda 130 Outboard.
Many people tried to put me off of the Avon, for various reasons, which all turned out to be wrong - and usually from people who hadn't been out in an Avon of any size or type - or those who hd had a 4 metre sea rider in the dim and distant past!
At our Training School we now have 2 Avons, my 620 and a 560 with a Mercury 90HP 4 Stroke.
These both perform extremely well, and we have had them out in all sorts of conditions, off of the North Wales Coast, in and around the Solent, English Channel etc.
I can personally recommend the Avon range, and I have tried various others, Ribcraft and Ribtec included, and would choose my Avon every time.