Not really, the performance of a folding bike may equal that of a straight bike. However, the one advantage that a folding bike has over a bike that cannot be folded is this. It is easy to transport or store. Thanks to its ability to folding into a compact design that takes a very limited space.
It is for this reason that most people that love camping or road tours will prefer folding bikes over the bikes that do not fold up. So as it is, it all boils down to what you prefer and what your biking needs are.