two usb midi interfaces?

before i spend the money on a second device to either replace or complement my existing, i wanted to know if anyone is using more than one usb midi interface?.. i already have a device from turtle beach that does the job, but it is only a 1x1 interface, and i have a need for a second… for <$50, i can pick up a m-audio 1x1 midisport… however, i’m concerned about conflicts arising between the two, especially considering that they are from different manufacturers… or are all of the device inputs consolidated to one single grand midi marshalling facility, and everthing will be okay?..

if anyone has any input on this, it would be greatly appreciated…

thanks in advance!