I use ecover multiaction spray once a week on mine and it’s fine, have been using it for about 2 years. The rest of the week I just use Ecloth dishcloths with water only. If it gets stained which is rare (wet teabags and curry can be problematic) I spray dettol surface cleaner on the stain leave for a few minutes then rub away. I’ve had white quartz worktops for 12 years now and not had any issue with damage/staining. They are pretty robust, I’m not careful with mine at all!

Quick update. I think I have found a needle in a haystack with help from the house community, Thankyou. Gemini Worktops have a quartz worktop, Siena Gold. I would describe it as a warm white with a subtle gold/ brown vein. The sample looks great against my kitchen doors and floor tiles. I have an appointment to see a full sized slab. I've attached a photo of the quartz sample on my floor tile with a sample of the kitchen cabinetry.

No, not all quartzes are made equal. There can be a big difference in the overall quality, the resins used and the amount of "stone" content. When it comes to Carrara styles, thee "realism" of Silestone (our "go to") & Caesarstone is generally much better and the whites whiter. Backup support is also much better. As to the recommendation of any fabricator - at the end of the day, their margin is in the labour & machining costs and they will protect that and view the "slab" cost as just that - a cost. They will protect their margin by "down-selling" you to a lower grade product to keep the overall sale. At the end of the day it is, of course, your choice - do you save £1000 today and opt for the cheaper, lower quality product or view it as a 20 year investment of just £50 a year. If it is your "forever" home, go quality. If you only intend to be there a year or two and just want the look, take the saving. As for replacing the granite - usually straightforward, only slight risk if there are tiles down to the granite and awkward "pinch" points but I've yet to see any major issues arising.

Its hard to tell because of the shadow that the upstand is casting. There should be more quartz at the back to allow for the tap. Mine is in the middle between the upstand and the sink. The quartz running past at the front is narrower. The tap is too close to the upstand. Was the quartz templated properly? Undermount sinks are normally fixed with their lip resting on a batten frame. Was this slightly off centre? It's not correct. I wouldn't accept this, its an expensive mistake.