...but I don't want to do it if the "next big thing" is coming around the corner. I'm eyeing the GF4 Ti series, but will wait if the GF5 is nearing its release date. Should I buy now or wait till later? Also, what's the difference between the different Ti series? A Ti4200 with 128 MB of RAM is going for $115 on Pricewatch right now, while a similarly equipped Ti4600 is going for $100 more. Why?