timethese $iters, {
        'eq !=' => sub { return $vartocheck eq lc($firstchar) },
        're !=' => sub { return $vartocheck =~ /^\Q$firstchar\E$/i },
};
__END__

% perl eqre 10000000
Benchmark: timing 10000000 iterations of eq !=, re !=...
     eq !=:  7 wallclock secs ( 7.42 usr +  0.00 sys =  7.42 CPU) @ 1347708.89/s (n=10000000)
     re !=: 26 wallclock secs (25.89 usr +  0.01 sys = 25.90 CPU) @ 386100.39/s (n=10000000)
Benchmark: timing 10000000 iterations of eq ==, re ==...
     eq ==:  8 wallclock secs ( 6.60 usr +  0.00 sys =  6.60 CPU) @ 1515151.52/s (n=10000000)
     re ==: 27 wallclock secs (27.77 usr +  0.00 sys = 27.77 CPU) @ 360100.83/s (n=10000000)