I have lived in Nailsea for many years, and I recently had the opportunity to live in Melksham for three weeks.  That gave me the opportunity to make this comparison.

The railway stations serving each town are far from central, but not beyond a good walking distance. There is no taxi rank at either, but cabs can be booked by phone. At Nailsea, there is a connecting bus service at the station, in both directions, with a reasonable service.

Both towns are historic: Nailsea has a claim to fame for coal mining, glass blowing and farming, and Melksham has a claim to fame for Regency spa facilities and a (disused) canal through it - as well as a host of other attractions.

The population of both towns is about 20,000.

(By the way: both towns have a Wetherspoons, and my preference is The Bear in Melksham over The Glassmaker in Nailsea.)

Chris from Nailsea.