I went from Vista 32 bit with 1GB RAM to Windows 7 64 bit to 8GB RAM, and I went with the 64 bit version solely because of the opportunity to have enough RAM not to have to worry about RAM anymore.
Between the 32bit and 64bit apps on my system, I don't notice any speed difference, and certainly not "pauses or weird glitches."
I started to say there is not much of an advantage to going to 64-bit on a 4GB system, but on a 4GB system, I think
64 bit would see the full 4GB vs 32 bit only seeing 3GB, so it might actually be worthwhile.
By the way, DO check all of your drivers, including the chipset drivers for your motherboard and Google what others say about running Windows 7 64 bit on your motherboard (or off the shelf system if that's what you have.) Vista 64 bit DID allow 64 bit unsigned kernel mode drivers, Windows 7 64 bit DOES NOT. In fact, Google every piece of hardware you have because I'm not seeing a trial version of Windows 7 64-bit except for one that runs in a VM, and that won't help as far as testing drivers.