Yes. The heat output provided by a radiator depends on several different design aspects, including construction material and size.
Generally, larger radiators will deliver a greater BTU output as they feature a bigger heat emitting surface area.
Similarly, double panel radiators will offer a stronger heat output than a single panel radiator of the same length.
Consult the BestHeating Radiator Buying Guide for a more detailed look at the various styles of radiators available, and the contrasting heat outputs they provide.