More then 4 user defined charsets

[atom]

There may be some rare cases where you *really* need that feature... but also there in most cases having a custom charset that include a little bit more chars (e.g. merge - the smallest - 2 of your 5 custom charsets or similar) shouldn't hurt much...

true, haven't seen a case where you actually need 5 without falling into a performance bottle-neck. if you really have such a case, maybe you should try hybrid attack, too