How much does RAM matter above 1 gig?

I have been thinking about getting a new Android phone for a very long time, and I am stuck between the HTC One X+ and the upcoming Verizon HTC phone that will have a 1080p screen.

I have pretty much resolved every question besides whether it matters that the One X+ has "only" one gigabyte of RAM. Do I need more than that? Do any of you ever have problems multitasking with one gig of RAM?