So I have read a few threads here so I think I have a understanding of the differences. The 640 will give a cleaner image at longer distances. The 640 has everything the 320 has, just better resolution at greater distance.
I am leaning toward the 320. My use case is walking around in the woods, around my neighborhood walking my dogs, eventually hunting. In my neighborhood the longest stretch would be approx 100yrds. Longest stretch of woods is approx 200yrds. I would use the 320 to detect targets and then use my AGM Rattler T35-384. I don't plan on shooting further than 200yrds.
I will be picking up a Rayvn dual bridge and already have a nice 3rdgen WP PVS-14 (bought last year from JRH).
Will I be disappointed in not spending the extra 1k? I can easily swing the 320 right now, and would have to pay off the extra 1k for the 640 over a few months. This will more than likely be the last time I can splurge on NV or fun gun stuff for awhile.
Thanks for any feedback.