1. Ease of Use: The Happy Australia and New Zealand 30 Days Unlimited Data Travel Sim Card is designed for convenience. It fits most phones and requires no registration, making it a plug-and-play solution for travelers. Users have reported that setting up the SIM card is straightforward, with automatic network connection within minutes of insertion.

2. Data Service: Offering unlimited data with 15GB of high-speed LTE, this SIM card caters well to heavy data users. After the initial 15GB, the speed throttles to 128kbps, which is sufficient for basic browsing and social media use. However, some users experienced connectivity issues in rural areas, which could be a significant drawback for those traveling off the beaten path.

3. Hotspot Functionality: The SIM supports hotspot usage, allowing you to share your data connection with other devices. While this feature works well on many devices, it's not guaranteed on all, so compatibility might vary.

4. No Voice Calls or Texts: A notable limitation is that the plan does not include voice calls or text messages. This aspect was not clearly highlighted in the product description, leading to dissatisfaction among some users who expected a more comprehensive service.

5. Overall Performance: For those primarily needing data services in urban areas of Australia and New Zealand, this SIM card performs adequately. It supports popular apps like Google Maps, Instagram, and WhatsApp without requiring a VPN. However, potential buyers should consider their need for voice services and their travel itinerary before purchasing.

6. Recommendation: If your travel plans are confined to urban centers and you require robust data services without the need for voice calls or texts, this SIM card could be a suitable choice. However, travelers venturing into rural areas or those needing comprehensive communication services might want to explore other options available at major airports.