Hey Tangled Up In Q,
A lot less work to build a UDS.
Less expensive is my guess.
Cutting both ends depends on what you plan on doing with the bottom of the drum.
My first drum I did that to make it real easy to lift the drum off of a stand that had the charcoal basket on it and clean the ashes up. But I never got a good seal, though I think it is possible. It did not hold temps very well sometimes and just was not good enough. These things really need to be pretty airtight to work well.
Another way is like Jaranimo did which was to build a short little drum out of a donor and weld a lid with the center cut out to the bottom of the UDS. Then you set the UDS on the little drum which is your charcoal basket. I like the idea just cannot do that welding and really don't want to pay for it.
So my second drum has the bottom still there and I built a charcoal basket with an ash pan that I can lift out and clean up. No trying to scrape the ashes out of the bottom of the drum, lazy old fat guy mod, I guess.
I also built a UDG (grill) for steaks, burgers and the like.