I'm having the same issue! I'm ripping out my shower and just assumed I would do a tile base but then my contractor mentioned onyx base. I like the looks of tile better but I also don't want to worry about grout or long term issues with tile. I don't know what to do.

I find that Maax enclosure to be quite attractive, as well as practical with the linear trench drain, built-in shelves, and lack of seams. It's undoubtledly needs less maintenance than tile, although a properly installed tiled shower with quality materials can hold up well too. Tile appearance varies considerably - the nicest ones are more attractive than acrylic enclosures IMO but many tiles don't look as nice as a clean, seamless enclosure.

If you're renovating the entire ensuite or if this is a newly constructed house, I'd probably rely on the walls surrounding the tub and windows to make the biggest visual statement, especially since you're using a freestanding tub. That's probably the first thing you see when entering the room through the sliding door.