Those bits should be Titanium Nitride coated, not solid titanium
. It then depends on the quality of steel that the bits are made out of.
Where I used to work, I drilled brass/copper/aluminum and the titanium Nitride coated bits always lasted longer. From what I remember, the TiN coating helps keep the bit cooler (could be wrong here).
I recomend them, but of course recommend quality bits.
Since we don't know the quality of those bits, I'd use them on some test pieces and make sure they don't break easily. Then when you do go for your production block, go slow, drill a thin depth, then back the bit off, go in for a bit more, then back off, etc... Make sure you use cutting oil/wax. I never went more than 1/8" deep before backing off, and usually went for 1/16" on average. Dewalt are over-priced. Can get a lot better quality bits from machine shop tool catalogs, etc.. for a lot cheaper than the Dewalts.