The Boori Waratah Breathable Mattress has a nice mix of comfort and support for your baby and it appears to be well made. A good quality option at a good price.
The TikkTokk Sweet Dreams Mattress feels a bit cheap and bouncy but functionally it is actually OK. Comfort and support should be adequate for your baby and it sells for a reasonable price.
The TikkTokk Sleep Eezi Mattress feels hard and cheap. You can feel the springs on slight pressure which is always a good indication of (poor) quality. Very basic but about right for the price.
The Sealy Cherish Cot Mattress has a good quality, durable outer cover with softer spongy pockets on the top layer. The top layer provides good support for a baby it seems well ventilated.
The Sealy Embrace Cot Mattress has a network of spongy but firm pockets on the top layer creating a nice mix of comfort and support for your baby.
The Sealy Snuggly Cot Mattress has spongy top pockets on the top layer which will be comfortable but they do provide good spinal support as well.
The Tasman Eco Orthopaedic Pocket Spring Mattress has a good quality outer cover and feels firm and supportive underneath. A little pricey but a good baby mattress none the less.
The Tasman Eco Essentials Mattress feels hard, cheap, and quite basic. There are better products available in this price range. Doesn’t appear to be particularly well ventilated.