I use both, but I’ve had more Maxtors go bad. To their credit, Maxtor hasn’t given me trouble with the RMA. With the WD, you’ll get the drive and nothing else, but I don’t really use the extra’s anyway. It may be different for you, however.
Good choice of vendor. My advice to you though is to avoid Maxtor until they get their act together and produce a better product. WD drives run cooler and have been much, much more reliable for me than Maxtor. (See: http://www.hardwareforums.com/showthread.php?s=&threadid=1257 .) I recently dropped one of the same 120GB WD drive you’re considering in a client’s system, and they have been thrilled with it. Either way you go on this one, hope everything works out for you.