I don't have an issue with either and have had
SEO success with both. I do think if you want to look unique and still use a premade one, that a simple design is the best, one that can be easily editted to look completely different. Browse through some of the design uses on oswd.org and see how they did it. Some are unrecognizable from their originals. There are some pay ones that are pretty complicated and hard to change, and thus wind up looking like the 40 other sites that bought them.
If you plan to sell the site later on, it might be better to start with a unique website, as some buyers prefer these to the premade ones so as there is are no issues that may come up.
Just some thoughts