No. A 70 inch gear is a 70 inch gear is a 70 inch gear, doesn't matter how big the wheel is, it's all taken into consideration when the gearing is calculated--one revolution of the pedals moves you 70 inches. In fact, accelation should be a little bit faster on a smaller wheel.

Quality of the ride is affected by several factors, and wheel size is just one. Bromptons, as mentioned, are famed for their rides, on their bikes the inherent shock absorbing inferiority of a small wheel is offset by the suspension and frame design.
Remember that all of these comparisons assume equal quality--all things being equal, a larger wheel gives a smoother ride, but top-notch 16" wheel bike will probably give a better ride than an entry level 700c bike.

Didn't mean to slag all 16" bikes in my first post--the Brompton is in a different category than other 16 inchers.