Question about matched/unmatched pairs of RAM

[CarpeDeo]

I'm running 128 megs of pc133 ems hsdram at 147 fsb. I'm seeing sooo many deals for cheap ram nowadays (micron pc133 for about 115) and would like to add another stick. Question is, does it matter whether or not I get matched RAM? Is it better to have two EMS sticks of RAM? Or will I get just as much performance out fo running a stick of ems and a stick of micron (assuming the micron can do 147 stable). Thanks!