Wood looks nice, but I think it's generally not the best choice for any sort of travel trailer for all the reasons you know:
- Suseptible to mold and rot over time
- Absorbs spills and moisture, and camping is almost always a damp environment
- Heavier than other alternatives
- Requires more upkeep than other alternatives
- Thermal expansion issues lead to gaps and buckles in floor, regardless if floating, or worse, nailed down.
So, other than looks, it's appeal escapes me. Alternatives?
AS itself has long used one-piece vinyl for a variety of reasons: Cheap, durable, relatively lightweight, low labor costs to install at factory, where it is laid down on top of the subfloor before the shell is attached and interior fixtures installed. After market makes this option unviable unless you are doing a shell-off restoration.
Vinyl plank flooring is a popular choice in either faux wood or faux stone options. It is available in a wide range of qualities, thickness, colors and patterns, is fairly durable, fairly lightweight and fairly easy to install.
Carpet is chosen by some, but besides being relatively cheap and easy, and feeling nice and warm after initial install, quickly gathers dirt and moisture and I wouldn't recommend it for that application.
Bamboo is another option some swear by; it's lighter weight than wood and a more sustainable product.
Others really like cork flooring; lightweight, softer than wood but easier to clean than capet, easy to install, easy to patch, and remarkably durable considering.
Some have taken a different approach and filled, painted and poly-sealed the subfloor directly, this option being cheap, easy, very lightweight and quite durable if coated with high quality polyurethane. Those that have gone this route have been quite creative with the flooring, painting maps or laying down picture collages, pennies, or doing something unique and charming to make the trailer their own.
I decided on a high quality, 3/4" thick puzzle mat material that has worked great. The formulation I purchased is very thermally stable with little expansion or contraction over the seasons. It is exceptionally lightweight, embarrassingly easy to install, looks great, impervious to water, easily cleaned (I can even remove a square at a time and hose it down, if needed) even replaceable piece by piece if damaged, and incredibly cheap, having spent less than $50 to do the entire trailer.
There are plenty of options out there and available, search the forums and you can even see pictures of what others are doing and have done. Good Luck!