I love having a 6 string, as you say offers a lot more versatility, particularly if your singer is prone to switching keys for songs. Get the odd weird comments but most folk think it is pretty cool and some how makes me a better bassist (little do they know). That said I have just finished putting together a precision copy for one of my bands because 6 string really doesn't look right for folk punk. I would go for it though mate, what bass was it you where thinking of getting?