whats the difference between these two?

[DeadAim]

I was browsing newegg for a 4850 for a new build when I was noticing certain makers for the 4850 and 4870 being purchased more so than others. Is it just company loyalty, or is there something about the maker or the card?

this is the asus 4850
Newegg.com - ASUS EAH4850/HTDI/512M Radeon HD 4850 512MB 256-bit GDDR3 PCI Express 2.0 x16 HDCP Ready CrossFire Supported Video Card - Desktop Graphics / Video Cards

this is the sapphire 4850
Newegg.com - SAPPHIRE 100242L Radeon HD 4850 512MB 256-bit GDDR3 PCI Express 2.0 x16 HDCP Ready CrossFire Supported Video Card - Desktop Graphics / Video Cards

prices relatively the same... so wht gives? what should i be basing my choice on?

[KarmaKiller]

Warranty and customer service. If you have the model already picked out, look for clock speeds(if that matters to you) and then the customer service is the next on my list, along with warranty. You want to make sure your card is covered. I believe ASUS has 3 year warranties, and the same with Sapphire. Visiontek has a lifetime warranty on most of their cards. I also believe Diamond does to.