I would say you are trying to compare two very different knives here. The Riv is much smaller, has a thinner blade stock. I love that size for EDC but for more heavy duty work the F5.5 is probably the better choice. The F5.5 is the same size as the Biblio so that should be the better reference. Here the F5.5 is clearly the knife with better build quality, also the Riv feels a bit higher end than the Biblio. If I recall correctly both the F5.5 and the Riv are made by Reate while the Biblio comes from Maniago. The Riv had the potential to be the ideal EDC knife for me but they should have kept it a liner lock. The frame lock does not make sense on such a small knife, it's basically impossible NOT to put any pressure on the lock bar which makes it more difficult to flick it open. I also don't like the titanium finish on the lock bar side (and on the presentation side of the titanium version). It is WAY too clean and too "vanilla". They should have given it a darker blast/tumbled look. Difficult to come up with a final judgement here. The Riv is nice, I love the design, the size... I will certainly carry it a lot but it left me wishing for something slightly different. The F5.5 is bigger, also a nice design and from what I have seen on social media everyone agrees that they put together a really nice knife all around!