My preference is run the worktop up as a splashback. It looks much cleaner and is far more hygenic as you don't have the grout lines which always need cleaning.

With the style kitchen you have posted it is quite common to use glass as a splashback too however you will likely find that if you have quartz tops then it will be cost effective to have a quartz splashback too as they may be able to get it out of the same slab.

My preference would be the Quartz

Just something to consider. This is only a digital render but try to consider the colour and warmth or coolness of the upper cupboards against the colour and warmth or coolness of the worktop. If one reads a warmer than the other and they are equal in terms of lightness then they might clash. Cool worktops and off white warm tiles or cupboards are tricky.

Additionally, any under counter lighting - get the best you can, with the highest CRI rating. LEDs vary greatly in light quality and temperature.

I would run the same material as the worktop up the walls, no question. Your kitchen is contemporary and tiles will not be slick enough.

Agree worktop material over tiles but have you considered a mirrored splashback? It really gives an illusion of space and brings in light. (Image courtesy Roundhouse)

Hey Zak! There's something timeless about matching the backsplash with the worktop. It creates a sense of continuity and makes the kitchen feel more expansive and cohesive. However, tiling the backsplash opens up a world of design possibilities. It's a chance to inject some personality into your kitchen and create a focal point that reflects your unique style. Ultimately, the decision comes down to your preference and the overall aesthetic you're trying to achieve. Good luck!