0.3 was quite some time ago – string performance was certainly a problem back then (an acknowledged one). String performance on 0.6-alpha, released last week, is very good. It should now be at least as good as scripting languages that have traditionally focused on strings (Python, Ruby, Perl). There are a few more tricks we could do in the future that could make this even faster, but they involve a fair amount of GC trickery, so we'll have to see.