Slightly overdue Mystique review below - would give it 8.5/10 (maybe take off a point/half a point if you don't have Marriott status, as some parts of my experience won't be applicable...)

I checked in after leaving Katikies at about 2pm. Check-in experience was OK although a tiny bit disorganized, it was the first day of operations but the room I had been allocated wasn't quite ready when I arrived, so I had to wait around a bit for housekeeping to finish cleaning/sterilizing. Check in staff weren't quite sure how long it would be so I was eventually given a quick tour and released to wait by the pool bar instead. I was booked in a Wet Allure Suite but was told I was being upgraded one category to a Spiritual Suite and was assured the room I was being given would be worth the wait (the manager checking me in said it was arguably better than many of the villas, as it had total privacy).

On eventually getting to the room it was clear he wasn't lying; I was allocated a suite at the bottom of the resort beyond Charisma restaurant, with none of the other rooms visible from the terrace outside - I think it's the Spiritual Suite photographed on the website. It had a separated living room and bedroom (albeit without a closing door between them), a small private gym off the living room, a large bathroom with a jacuzzi tub / shower in a separate room and then the spectacular terrace overlooking the caldera with a large hot tub outside. The style of the interiors is deliberately minimalist but is a lot more modern than Katikies; almost everything about the hard product in the room at Mystique felt better / more premium, frankly. The air conditioning was a lot more modern / effective. It was also nearly twice the size, which helped!

Only one infinity pool here, which is located at the bottom of the resort. It's a similar size to the main Katikies pool, so more for chilling out / Instagramming than doing laps, but the view probably partially makes up for it. Service by the pool was much more efficient / attentive at Mystique. The hotel normally has three restaurants: Charisma (Greek/Mediterranean), ASEA (Japanese) and Captain's Lounge (casual), but only Charisma was open during my stay. I think Captain's Lounge may also have a second (non-infinity) pool next to it when open.

Service was generally very good throughout, I would say the service style at Mystique is probably slightly less traditionally Greek and a bit more adapted to American guests who probably expect things to happen in a certain way, but as a somewhat uptight Northern European who doesn't like to wait for things, it suited me fine . The one real service slip up was at dinner at Charisma on the first night, which had great quality food but it was clear they just weren't organized yet; service took forever and they managed to mess up some people's orders. Breakfast at Mystique was similar quality to Katikies, but with a more extensive menu and more non-Greek choices.

Felt very sorry for the bellboy staff lugging the suitcases up and down, whilst Katikies has a lot of steps, Mystique has more! It's a genuine work-out to get back up to street level when you're down by the pool.

Overall then, Mystique was just slightly more my taste overall than Katikies. I'm deducting half a mark for the check-in experience, half a mark for the dinner on night one and half a mark for the lack of a pool that's big enough to do laps in. Already planning a second stay in a few weeks, though