Funny, I'm a leftie too, and hadn't noticed one phone being better than another for us southpaws.
Though the US carrier-version of the Galaxy Nexus doesn't seem to get updates as fast as the GSM unlocked version, it's still a selling point because it is ahead of other brands for updates. Heck, most other brands don't even has ICS yet! If you liked the Samsung Fascinate's display, you might like the Super AMOLED Galaxy Nexus' display better as well. The HTC Thunderbolt was Verizon's first LTE phone and is long in the tooth, and the HTC Rezound is leaps and bounds ahead. It has a more color neutral and accurate display, but it lacks that Super AMOLED wow factor for vibrant colors and deep blacks (a matter of taste as to which you prefer).
You can always pick up a nice set of headphones, but if you want the latest OS, prefer the control location of the Galaxy Nexus and like Super AMOLED displays, I say go for the Samsung Galaxy Nexus.
-------------------- Lisa Gade Editor in Chief, MobileTechReview