I have a set of Forstner bits, from Rockler, as well as from others.
Good price for the larger set from Rockler.
I've drilled lots of holes with most of them, and they've served me well for several years.
I touch up the cutting edges, to keep them sharpened, using diamond steel files, such as the machinist files, offer by EZE-LAP.
I've found most cheap bits, do not have the brad point "centered",
as well as not keenly sharpened to provide a clean cut hole.
I've found many to also have burrs on the cutting edges.
If the brad point is off, by even a 1/64", you'll not get a good clean hole.
If you only need a small number of sizes, and plan to drill lots of holes on a daily basis,
then get a higher quality made bit.
I've been extremely disappointed with the Diablo bits. The fact that the are a Freud product makes them even more disappointing. I had a 1½" Diablo that lasted one 5/8" deep hole. I found the Woodtek brand on Amazon that works well and lasts. I needed a 2½" inch to bore out the inner diameter of bracelets on a lathe. It has worked perfectly for 15 bracelets ranging in thickness from 5/8" to 1¼", even though my lathe won't slow to the recommended speed. I also ordered 1-9/16" & 1-5/8" bits for boring cups to hold tea lights and votives, and they also performed much better than the Diablo. I have a set of Porter Cable bits for sizes 1-3/8" and under that I've never had an issue with.
As Ken mentioned, I do touch up the cutting edges with the EZ Lap diamond hones before each use. If you are cutting into pine, cedar or other soft woods, be sure that pitch is not building up on the bit, as well.
I've used the Diablo drill bits, and didn't experience any problems.
Prior to use, I keenly sharpened the cutting edges, and they performed without any problems.
They cut as clean as others I've used.