Ever since I destroyed my second inertia puller about 15 or 16 years ago, I have used nothing but a collet puller. Some of the bullets I have pulled were pretty hard to get out, due to cold welding, crimping or whatever. Most of those were fairly deeply compressed where the collet had grabbed them. They did not perform noticeably different from any others that I had pulled using either method.
I would worry more about minimizing runout than how they look.
If I ever saw that they were crimped or found that they were cold welded, I took an extra step in the process and re-seated the bullet a tad deeper to break that bond. After that, I'd find pulling the bullet was much easier.
