Ideally, I'd want a toilet in any bathroom, but if I could only have one toilet in the property, for me a separate one is essential. Otherwise, if someone is having a leisurely soak in the bath and someone else is desperate to use the toilet, you've got a problem. We are combining the separate bathroom and toilet in our current renovation, but also adding an en-suite toilet was a priority (no space to include a shower, unfortunately). If we hadn't been able to do that, we would have kept the bathroom and toilet separate.

Having been raised in the USA, where the 1/2 bath is often combined with the laundry space, it's much nicer to have it separate if possible. Since the toilet is often for the use of guests, why would you want your laundry on show?

However, if the combination of toilet and laundry room would allow a shower, then that's an even better option!

Having the toilet separated from the bathroom is a rather dated look in todays world unless it is a downstairs guest toilet.

We prefer to have the bathroom separate.

Kibre Ltd, I agree that combined bathrooms and toilets are more popular these days. Perhaps that it because most homes (well, at least most houses) now have more than one toilet, whether a separate downstairs cloakroom or one or more en-suites, removing the need for the sole toilet to be more accessible.

I find that most of my clients are opting for a combined bathroom and toilet space

Both, if space allows. I am lucky to have a house with a bit of extra space so have a shower room with a loo in it and a separate loo with a basin. My regret is that the layout of the house didn't allow for the separate loo and basin to be on the ground floor (what a first world problem!). But I've been really glad to have both options.

Ideally it is nice to have a WC as well as a main bathroom, but otherwise, a bathroom with the toilet built in just makes more sense.

We have a guest who is in a wheelchair, to be able to have a all in bathroom like the picture on the left on the ground floor would be great.

I grew up in a house where the toilet was separate from the bathroom, so that arrangement seems normal to me. What makes me prefer that now is the hygiene aspect - when you flush a toilet, apparently some fecal matter becomes aerosolised and can settle on your toothbrush, towels, etc...yummy!
Having a shared bathroom and taking a shower after someone else has 'dropped their kids off at the pool', isn't particularly pleasant and air-freshener just highlights the issue.

Easier with a family.

2 spaces are sometimes better than 1

It is cost-effective way

If you've got a lot of people in the house, the more loos the better.

Even when space is limited it always seems less outdated when the two are combined. When together it appears to give a feeling of grandeur and feels complete when there is a toilet in the bathroom. Practically I agree separation has its benefits; great for families and the when the laundry area is combined: its not totally visible to visitors, but to me it feels like my childhood feelings of the 70s; outside toilet syndrome.