I'm going to go way out on a limb here and say that the Bose speakers in an 04 maxima are slightly better than the ones in a 94 Q. I replaced my HU in my 01 Max and the speakers sounded 100% better. Besides, I'm sure the speakers sounded better in your Q but you had more power and volume and were able to get to the distortion level easier.
I think the 04 setup is similar to mine, in which case I would say if you are thinking about it then do it. You can go to
http://www.crutchfield.com and enter the exact specs of your vehicle and it will show you exactly what is required to replace it. Check it out!