Fastest boats ...30 to 35 foot range.
That is a bit of a tough question and one that would be easier to ask if I knew where you are coming from. If you mean just plain maximum speed, there are 30 foot semi-custom foilers that hit outrageous speeds well up in the mid-20 knot range. These are one trick ponies that really do nothing but go fast.
Then there are the current crop of high perforance trimarrans which are very fast, for boats that also offer some accommodations, offering speeds well up in the high teens.
In the case of monohulls there is a new 30 foot carbon fiber tripple trapeze one design that I saw a write up on. I would suspect that will be as fast as any of the current crop of 30 foot monohulls.
More conventional (and older designed) monhulls that are quite quick would include the Mumm 30, Melges 30, Carrara 29, One Design 35 and one design race boats of that ilke.
But fast does not mean competitive because ratings come into play when you go racing and ratings treat some boats fairer than others.
On the other hand if you are actually looking for a fast boat that can also be cruised, that opens an entirely different discussion if you see what I mean.