When I first started making pens in 2008 I got a collection of pre-cut & drilled Rosewood blanks. They were just the right length for Slimlines or comforts with little or nothing to trim and easy to glue up and turn.
The biggest problem I had with them is they weren't matched sets, which made it a bit of a challenge to find two with similar enough grain structure so they looked like they came from the same piece of wood. If you're just cranking pens in numbers this isn't a big deal, but if you're wanting the pen to look uniform in color and grain from top to the bottom, it's not the best solution.