If you're car has DRLs Silverstars are definelty going to blow early since the electrical surge when the car is turned seems to reduce their life greatly. I had a couple set on my 4Runner and both sets lasted over 2 years. Ultrastars seem to have longer life but I still wouldn't use them with DLRs and I always make sure my headlamps are off when I start my vehicles. The light output is better than OEM bulbs but I'd do some research before you spend alot of money on any pricey bulbs.
I want to replace the ones on the Focus but I'm in no hurry.
'12 Focus Red Candy SE Sport 5 spd
'99 Toyota 4Runner Sport
'11 Subaru WRX STI Hatch