If you want one answer: buy the hand-wound fake IW545104 with a decorated movement under a display back. That is the only tier where the watch in your hand behaves like the reference it copies, because the IWC Portugieser Hand-Wound 8 Days line is built around a hand-wound calibre, a long eight-day power reserve and a small seconds subdial sitting at 9 o'clock. I judged every option below on four points: the movement and how it winds, the dial printing and subdial position, the case and crystal, and the strap, buckle and crown. Those four decide whether the watch reads right on a wrist or falls apart under a loupe.

What the genuine reference sets as the benchmark

The IW545104 sits in a family defined by restraint: a clean dial, applied markers, a small seconds register at 9, a slim bezel and a display caseback that shows a hand-wound movement rather than a rotor. Before you shop a replica, pull the official specification sheet for the exact reference and write down the case measurement, crystal type, dial layout and whether a date window exists on that model. Most bad fakes give themselves away on that last point alone, because sellers reuse one case and dial across several references.

Option 1: Quartz and battery builds

The cheapest tier. It tells time and it photographs well from three feet away.

• Pros: low cost, accurate timekeeping, light on the wrist, easy to replace.
• Cons: the seconds hand ticks instead of sweeping, the winding crown does nothing, the subdial sweep is wrong, and the caseback shows a flat plate instead of a movement.

Use case: costume and single-evening wear. Do not buy this if anyone at the table knows the reference.

Option 2: Automatic builds

Mid tier. These use a self-winding movement in a case copied from the reference.

• Pros: sweeping seconds hand, decent weight and balance, serviceable movement, better dial finishing than quartz.
• Cons: a rotor sits where the genuine watch has none, so the display back tells the wrong story; the subdial on many versions sits at the wrong position; hand sizes and marker heights drift from the original.

Use case: daily wear for someone who wants a wrist presence and never takes the watch off to wind it.

Option 3: Hand-wound with a decorated movement (top pick)

The tier I would spend on. A manual-wind movement, a display back with decorated bridges and screws, and a subdial placed at 9.

• Pros: the winding ritual matches the real watch, the subdial sits in the correct spot, the caseback shows a movement that belongs to the design, and the case profile stays thin.
• Cons: higher cost than the tiers above, no automatic convenience, and you should budget for a service or a movement swap if it stops.

Use case: anyone who removes the watch to wind it and wants the back of the case to hold up when a friend turns it over.

Criterion: dial and subdial execution

The dial is where money shows. Check the subdial position first, then the printing, then the markers.

• Subdial at 9 o'clock, not centered and not at 6.
• Text lines that stay sharp under a phone macro shot, with no blur or double edge.
• Applied markers with polished edges and flat tops, seated level with the dial.
• Hands that reach the minute track instead of stopping short of it.

Criterion: case, crystal and caseback

Ask for the measurement in millimetres and check it yourself with calipers if you can. A case that runs a millimetre or two wide changes how the watch sits.

• Sapphire rather than mineral glass, and check for an anti-reflective coating by tilting the watch under a lamp.
• Caseback engraving with clean edges and correct spacing, since shallow laser etching is a common shortcut.
• A display back with a fitted crystal, not a flat disc pressed into the case.

Criterion: strap, buckle and crown

A good head on a cheap strap still looks cheap. Look for a leather strap with stitched edges and a grain that runs in one direction, a signed pin buckle with a solid tongue, and a crown that is proportionate to the case with a logo that is struck, not printed.

Which tier fits your use case

• Occasional dress wear and photos: automatic tier is enough.
• Daily wear with a winding habit: hand-wound tier.
• Costume or a gift for someone who will not inspect it: quartz tier.
• Displaying next to other watches: hand-wound tier, and budget for a strap upgrade.

Questions to ask before you pay

1. Which movement is inside, and is it hand-wound or automatic?
2. What is the exact case measurement in millimetres?
3. Is the crystal sapphire or mineral?
4. Can you send photos of the actual piece, including the caseback and the subdial close up?
5. What is the return window if the dial printing is off?

A replica stays a replica, and no replica carries the warranty, service history or materials of the genuine watch. Buy the tier that matches how you will wear it, verify the four points above with photos of the actual unit, and treat any seller who will not send them as a seller to skip.