For one-off runs it doesn't feel slow, but it gets more noticeable if you're running it in a loop or against a server you know is fast (i.e. local Go server), but consider this output as an example (running from an AWS server):

  # time http google.com >/dev/null 2>&1
  real 0m0.337s
  user 0m0.259s
  sys 0m0.036s
  
  # time curlie google.com >/dev/null 2>&1
  real 0m0.042s
  user 0m0.011s
  sys 0m0.005s
  
  # time curl google.com >/dev/null 2>&1
  real 0m0.039s
  user 0m0.009s
  sys 0m0.004s