I contemplated one time on getting it or Call of Duty. I got Call of Duty instead (for the PC) and am so glad that I did. Dont get me wrong, everyone I know that has played BF1942 loves it also but with CoD you CANNOT go wrong. I can answer your question though due to never playing BF1942. Sorry.
I will reccomend CoD though for the PC it is great. The expansion pack is even better. I have not played CoD2 due to my PC not being strong enough.
BF1942 is not a bad game at all though. If you like WW2 stuff you will not be wasting your money at all. Give CoD a shot too!