A well set up Vincent is a very nice bike to ride indeed. Actually, the light weight, instant torque, and small physical size, makes them great in traffic.
Because they are physically small, other road users often think it’s a very small bike, and treat you accordingly, so upgraded electrics to allow constant use of the brightest lights are a good idea.
There are many proven mods available, EI, E start, Mikuni carb kits, suspension upgrades, etc, etc. So they can easily be made into a very useable and very fast classic.
I have personally never ridden one with standard brakes. Those who have claim they are good when set up properly, but I cannot comment on that. Mine had a 4LS drum in the front which was excellent. And only half a rear brake, which was shite !
Set up right, they are a first kick starter, handle well, go fast, and easily handle high mileages.
Bottom line is, if you want one, and can afford one, you‘re highly unlikely to be disappointed.
Getting a good one, rather that a shiny money pit, is probably the hardest part.
Restoring one is very involved indeed. They are totally different to any other Brit bike. And many did very high mileages over the decades and are utterly worn out inside !
If you genuinely want one to ride, I would highly recommend an Egli Vincent Godet.