FWIW, Sylvania is in a class action lawsuit with the Silverstar and Silverstar Ultras. Something about false claims or something. I have them in my Tahoe with daytime running lights and they have lasted at least two years. I like them. They are a little whiter but I'm not sure it's any brighter.

As for the 4 Hi mod, it is very easy with a little know how. All you're doing is using a relay to send a secondary power source to the Low beams, using the power to the high beams as the energizer for the relay. So when the high beams cut on the the low beams go off, you tap power from the high beam feed to cut the relay on, which then feeds power from the power source(battery or power terminal in fuse block, NOT HIGH BEAM LINE) to the low beam.