If you're willing to pay ~$200 more for the extra features on the Asus X99 Deluxe, I'd say go for it. Otherwise, from what I can see, the Gigabyte X99-UD4 has everything a normal user would need.
In terms of reliability, it's a tough question. I haven't seen any statistics that decisively prove one brand to be superior over the other, bearing in mind that QC differs from board series to series, even within the same brand.
In terms of warranty and support, there's plenty of anecdotal evidence either way for both brands, and support differs from region to region. If Gigabyte has provided good support for the two times your board failed, I'd say just stick with them.