If you plan on magnum velocities, pick up some more checks.
If you can keep the throttle down, open base is fine.
When you size and lube your bullets without the check, you get a fairly sizable lube ring on the base of the bullet. More lube never hurt anything. It can lead to some tricky seating problems if you don't watch yourself though !
If you can spare the extra few cents per bullet, you'll reduce your lead fouling quite a bit... if that matters to ya !
If you are looking for the upmost guaranteed accuracy, use the checks. The base of the bullet steers it, for what that is worth.
Most people who shoot my 44 can't see a difference in accuracy with or without the check... YMMV. With a bag and a table, I can see it. Without a bag and a table, I'm just not that good yet.
I've looked into the check makers listed above. Once you factor in the tooling cost, the copper cost, and the time of manufacture... it wasn't worth it to me for checks that were commercially available. I'm a cheap SOB, and I still wasn't willing to go that far to literally save a penny per shot, at the absolute best. Now, if Hornady goes out of business or something........ With that said, its a personal choice, and hand made checks can be very high quality.