Seems like it is to each her own on how to avoid claustrophobia. I am very bad with this and as such am fanatical about aisle seats, and bulkheads whenever possible. For me, it's the feeling of being trapped in a tight space without the possibility of getting up/out that is the killer, so a window seat in a 3-across configuration is the absolute worst thing I can imagine. I will offer to swap for the middle seat when I am stuck with a window, just so I can be closer to the aisle--it makes me feel better. (Once when I did this, explaining my rationale to the now-ecstatic middle seat guy, the aisle seat guy heard me, and in a moment of stunning graciousness, gave me his aisle seat and moved to the middle himself since he said he'd be sleeping anyway. I couldn't believe it.)

I also find larger planes a lot easier to deal with than RJs, although this hasn't been an issue except when I'm stuck for hours on the tarmac in an RJ. In cases like that I just have to resort to deep breathing to keep myself from having a panic attack. It is not pretty.