With nowhere anywhere relatively close to audition them its kinda hard. Or any speaker, for that matter. So I'm trying to go by the next best thing, expert ( occasionally ) opinion.
Without any real way to audition them, its kind of a coin toss. Both Polk and Energy have their fan base, and unfortunately audio is one of those areas where there is no clear cut "best". Of course if all else fails, you can choose by aesthetics, service, and importantly, return policy.
) opinion.