You're using the same aspect ratio (16:9) so it really shouldn't matter. I think its just a visual adjustment thing and you'll be back to the same skill in short time. I do all my gaming (console and PC) on a 40' 1080p HDTV, and I don't find it even makes much difference when using different aspect ratios and resolutions with PC games. Of course I'm really quite poor at online games, so maybe that's the difference.
