Conclusion: The Olympus DS-3500 is a capable digital voice recorder with a focus on security and office workflow, but unless you work with a lot of sensitive information, it's difficult to justify the high price tag.
Pros: Fast and responsive. Sensitive mic. High recording capacity. On-the-fly index marks for noting important points in a recording. Can adjust playback speed without affecting voice tone. Voice-activated recording. Real-time file encryption and password protection.
Cons: Very expensive. No automated transcription. Features and software take time to learn to use.