I'll chime in a bit on this one (thanks for the nod Nate!)

The Purple Barney "Game Converter" is pretty unreliable and the Mirai converter isn't very good either. The guys at TZD even told me that the Mirai is unreliable, particularly with the Arcade Card Duo. The "unreliable" nature for many converters is due to the ridiculously long leads on the converter which short on the HuCard slot if the converter isn't seated perfectly or moves a bit crooked in the slot during gameplay. The Kisado is generally considered the best since it's made very sturdy compared to the others, it fits all systems, and it tends to move the least in the slot due to to its dimensions. But of course these generally cost you $100

For half that I can mod your system such that you use a switch to do the same process. (I have a thread in the B/S forum with some examples).

The main argument against the switch mod is that it'll "hurt the value" of the system from a "collection" standpoint. But if you plan on playing your system and want it to look good and not fear losing the converter, the internal mod is the way to go. I have the Kisado adapters but still preferred the mod solution (and I swear that's not a sales plug!!)