Saw your OP earlier, it seemed that if you unlock the bootloader & root it, and flash one of the custom Rom available via XDA-Developers dot com, you might experience better performance & overall responsiveness - from what I was reading on their site. Unless you purchased extended warranty, tech support @ VZW won't be able to much for you - sometimes, they will allow early upgrade as it sounded like you plan to renew & upgrade to their current offering. If you have a corporate rep. assigned to your VZW account, it wouldn't hurt to ask after having tech. support put notes on your support history in their system.

Are you running stock Gingerbread or was it upgraded to 4.1 Jelly Bean? Hardware/specs. designed for GB roms generally don't do that well with JB upgrade, despite some of the best work done via XDA geeks.

Since this is a global phone, it's worthwhile to keep it as a spare - if the Sim slot hasn't been unlocked, you should call up Global Support & ask them to provide you with the free unlock code while it's still active & in good standing for the account, so that you can use it with any Sim card, as the HSPA bands (not so much the LTE) would at least give you 3G data access, that's useful if & when you travel abroad. It will also enhance its eB** pre-owned value if it is in good to excellent condition & choose to sell it, although they generally don't get much vs. iPhones or other equivalent GSM devices.