Equal sized strings.
Benchmark: running bquoteDiff, bquoteSame, join, loopBeg, loopMid, loopSame, quote, each for at least 2 CPU seconds...
bquoteDiff:  2 wallclock secs ( 2.02 usr +  0.00 sys =  2.02 CPU) 
@ 21153.73/s (n=42794)
bquoteSame:  2 wallclock secs ( 2.05 usr +  0.00 sys =  2.05 CPU) 
@ 10422.80/s (n=21398)
      join:  3 wallclock secs ( 2.10 usr +  0.00 sys =  2.10 CPU) 
@ 31310.51/s (n=65846)
   loopBeg:  2 wallclock secs ( 2.14 usr +  0.00 sys =  2.14 CPU) 
@ 30084.42/s (n=64501)
   loopMid:  2 wallclock secs ( 2.08 usr +  0.00 sys =  2.08 CPU) 
@ 13698.51/s (n=28534)
  loopSame:  2 wallclock secs ( 2.09 usr +  0.00 sys =  2.09 CPU) 
@ 8104.16/s (n=16962)
     quote:  3 wallclock secs ( 2.13 usr +  0.00 sys =  2.13 CPU) 
@ 20563.53/s (n=43862)

Different sized.
Benchmark: running bquote, join, loop, quote, each for at least 2 CPU seconds...
    bquote:  2 wallclock secs ( 2.24 usr +  0.00 sys =  2.24 CPU) 
@ 31813.73/s (n=71390)
      join:  1 wallclock secs ( 2.13 usr +  0.00 sys =  2.13 CPU) 
@ 44310.68/s (n=94559)
      loop:  3 wallclock secs ( 2.00 usr +  0.00 sys =  2.00 CPU) 
@ 57423.08/s (n=114961)
     quote:  1 wallclock secs ( 2.11 usr +  0.00 sys =  2.11 CPU) 
@ 32110.27/s (n=67849)