Hi, i recently have got back into giging and recording my rig is pretty bassic but nice i run my 2 basses to a hartke half stack rig i have a chorus pedal and a fuzz pedal. im recording alot lately and im looking at a di box mainly the sansamp and the mxr. whould a DI box be usefull when playing live?
A DI will help you in a live situation if you want your bass to go through the PA.
Both the units you mention (assuming I'm thinking of the same MXR) will shape your tone and/or add some distortion/dirt/overdrive. They are multi-purpose i.e. pre-amp plus DI and they are both (generally) valued more for their tone shaping abilities than as a DI.
Many people choose to use a transparent DI (that is only a DI) that can reproduce your sound pre or post pedals as accurately as possible e.g. Radial JDI, Countryman etc etc.