The honest way to compare these is to say what each is built for. Oxygen Forensic Detective is a broad, enterprise-grade forensic suite. It acquires and analyzes mobile devices, computers, drones, vehicles and other device classes, it extracts from more than a hundred cloud services and it covers tens of thousands of device profiles and app versions. It is a serious platform for a lab that needs to work everything. This page does not pretend otherwise.
Sherlock Forensics iPhone Analyzer is deliberately narrower. It does iPhone and iPad, on Windows, doing that part deeply for a one-time $599. It is not a multi-platform suite and makes no claim to be. The comparison below is therefore not about which tool is better in the abstract; it is about a specific question: if your device work is mostly iPhone and iPad, do you need the whole breadth of Oxygen for that piece or does a focused analyzer at a fraction of the cost cover it. For many firms the honest answer is the second one.