Balsawood V's Paulownia

Here are some points of differences –

Balsawood is half the weight of paulownia. So your boards and kits will be 30-40% lighter.

Balsa wood and paulownia are both lightweight woods, but they have some differences:

Density and Weight: Balsa wood is known for being extremely lightweight and has one of the lowest densities of any wood. Paulownia is also lightweight but is denser and 50% heavier compared to balsa.
Strength: Balsa wood is not very strong or durable compared to other woods. It's known for its softness and low strength-to-weight ratio. Paulownia, while still lightweight, is stronger and more durable than balsa wood. It has better structural integrity and is often used in applications where some strength is required.
Applications: Due to its lightweight and buoyant nature, balsa wood is commonly used in model making, crafting, and even some construction applications where weight is a concern. Paulownia, on the other hand, is used in a wider range of applications including furniture making, musical instrument construction (such as guitars), and even in some boat building due to its strength-to-weight ratio and resistance to rot.
Grain and Appearance: Both woods have a relatively straight grain, but paulownia tends to have a finer texture and a slightly more pronounced grain pattern than balsa wood. Paulownia often has a light, creamy colour, while balsa wood can range from a very pale cream to a light brown colour.
Freight: Balsa being lighter you will have on your freight costs.
Flex:The building tasks to be able to bend balsa is a lot easier giving you better joints fewer joins and more rocker in your overall board.
Wear and Tear: There is less wear on your tools and machinery and easier and faster cutting and sanding. Due to a high silica content in a paulownia, the wood can have a strong blunting effect on cutting edges.
Resin:Resin will absorb and stick to balsa better because the grain is more open. So a better bond will occur.
Weight:Balsa weights average 150kg/m3 and Paulownia is 300kg/m3

Overall, while both kinds of wood are valued for their lightweight properties, paulownia is typically considered stronger and more versatile to building furniture compared to balsa wood more suited for surfboards.