Guest bathroom shower surround, glossy white tiles, "regular" TEC grout, 2008 I think. MB and hall bathroom tub surrounds, glossy white tiles, TEC XT grout, 2011. No issues. The XT grout doesn't require sealing, but can be, using a solvent based sealer. We have moderately hard water. We wipe down the tub surrounds with a microfiber cloth after showering (to prevent water spots on the glossy tile). I clean the bathrooms pretty much weekly. I spray the tub surrounds with 7th Generation disinfecting bathroom cleaner spray. Let sit a few minutes, and wipe dry with a microfiber cloth. Tile and grout look as they did when first installed.

Bought Florida Kerala Karma wood plank tiles and cant decide on what color grout to use.

I usually like to match a mid-tone from the tile, unless the grout lines are an important part of the pattern. what exact color depends on brand and specific tile, so you need to get samples and set them next to a sample tile to choose.

I agree with chispa, darker grout will show installation imperfections and will look really busy. I'd go with a light-medium color. It will be more forgiving when it comes to keeping it clean looking. White will be nice and subtle. Personally, I love subtle: let the texture be the interesting pattern, not the color. But if you're tiling behind a stove, it might be troublesome to keep it clean. Here is a darker medium: And a lighter medium (personally I like this one):