Sonar Producer 8: Huge differences between 32 vs. 64 versions?

Hi, folks!
 
I just upgraded from Producer 6 to 8. What I thought was going to relatively inexpensive became much more expensive when I realized I would have to ditch my old Pentium 4 desktop with 1mb RAM and spring for a faster computer. So, I ended up getting an HP Pavillion Dual Core on sale at Staples, with a 600gig hard disk and 6gig RAM and (yech!!!!!) Windows Vista.
 
Anyway, I managed to move my Emu 1820 sound system into the number computer and copied all my legacy CW projects. When I installed Producer 8, I chose the 32 bit version because I wasn't sure whether my legacy Emu interface would work in a 64 bit environment. I installed all four disks that came with the package and then upgraded to 8.3.1.
 
My question: Is there a huge difference in terms of sound quality, speed and performance between 32 and 64 bit? I use CW mainly as a MIDI sequencer driving hardware sound modules that record audio in CW. I don't use that many softsynths (yet), and I don't use a huge number of effects.
 
And if you convince me that 64-bit is so much better, do I have to totally reinstall everything (i.e., uninstall CW alone, reinstall from disk, and then reinstall th updates? Do I also need to uninstall all stuff (Dimension Pro, etc.) on the other DVD ROMs and then reinstall? This would be such a pain--it took nearly two hours to install, register, get the updates, and get it all together last night.
 
Jeff