One reason I prefer Package version over Application version is because that's how RIM lists it in the Vendor.xml file - it's easier to know when an obscure new version has been released or is set for release. It's listed as the 'release version' for a reason.

With that said, the latest one available for 7100 family is 4.1.0.351 (multiple carriers); 4.1.0.380 for the 7520 (just issued from Nextel).