Which is better for beginners?

The Flick. Retractable needles are harder to bend and safer to handle, and the included stand keeps it tidy on the counter.

Both use replaceable steel needles, so wear depends on the needles, not the body. The Flick's retracting mechanism is the one extra part that could wear; the Wiedemann's wood needs to stay dry.

Is the Wiedemann worth stepping up to?

Only if you want the walnut look and the HangUp rack. On function the Flick gives you more needles, a stand and safer storage.

Do they distribute grounds the same way?

Yes. Both use thin needles to break up clumps before tamping. The Flick lets you pick 0.35 mm or 0.5 mm needles; the Wiedemann ships with one needle type.

Can I travel with either?

The Flick travels better because the needles retract. The Wiedemann's fixed needles need care in a bag.

Which fits a 58 mm portafilter basket?

Both work in standard baskets. The Wiedemann is longer at about 120 mm; the Flick is shorter and sits in its stand.

Wiedemann WDT Tool vs Subminimal Flick WDT Espresso Tool

Buy the Subminimal Flick if you want a safe, retractable tool with a stand and plenty of spare needles. Buy the Wiedemann if you value a hand-finished walnut handle and German build. The Flick has far more owner feedback and its retracting needles protect fingers and bags. The Wiedemann has a warmer look and a magnetic rack system, but only eight needles and two spares.

Choose the Wiedemann WDT Tool if you want a walnut-handled tool that matches other Wiedemann wood gear and mounts on the HangUp rack.
Choose the Subminimal Flick if you want retractable needles, a stand and six spare needles in a stainless steel body.

Prices

Wiedemann WDT Tool: $50.00 at Whole Latte Love (checked today)
Subminimal Flick WDT Espresso Tool: $10.59 at eBay (last seen Nov 9)
Difference: the Subminimal Flick WDT Espresso Tool is $39.41 cheaper than the Wiedemann WDT Tool at the latest prices (Nov 9 and Nov 12)