I'd never heard that argument before so I did some testing out of curiosity...

    require 'benchmark'

    hello_string = "hello"
    hello_regex = /hello/
    pad = "A" * 10000
    body = pad + hello_string + pad

    puts "Match method:"
    puts Benchmark.measure { 100000.times { body.match(hello_regex) } }

    puts "Include method:"
    puts Benchmark.measure { 100000.times { body.include?(hello_string) } }

Results using 1.9.3p484 on a Mac:

     $ ruby bench.rb 
    Match method:
      0.880000   0.000000   0.880000 (  0.879181)
    Include method:
      1.350000   0.000000   1.350000 (  1.351293)

I am curious of the scenario where it's considerably slower/faster, but I can change it if that's more conventional since it seems pretty comparable given my contrived amplifiers.