I've had my tiles for 7 yrs, wash my bike and cars in the garage, and do not have a problem...I live on the Georgia coast. Epoxy vs tiles...there are benefits to both. Tiles are easy to install and replace if damaged. Anything with a sharp metal edge is going to gouge tiles, especially if it slides across the floor. You actually mentioned "paint" in your original post - if you use paint (verses epoxy, etc), you're wasting your time. It will not last and has no durability.
If you've researched epoxy, you know the prep of the garage floor is the key. The most expensive epoxy on a poorly prepped floor will be a waste of your $$. Also, the low cost epoxy kits from Lowes & Home Depot will not last. You'll want to go with an industrial grade epoxy (go to the forums on Garage Journal...there's plenty of flooring info there). When I was researching epoxy there was an industrial grade product called Rust Bullet that I would have purchased if going the epoxy route.
Lastly, if you go with tiles, try to purchase them in the summer and leave them outside in the sun. After they heat up, install them. This will allow you to install the tiles at their max size, so they will not buckle (this is a tip from RaceDeck). Good luck.