I've had a few hours on this now and X55 controller lack of mapping aside (argh!!!); I'm really impressed.
Lighting, shadows and reflections, everything graphically is a big step up from what I've previously seen in a sim. The Bing maps scenery data and auto gen are a game changer. Previously you would have to pay hundreds for VFR scenary just to cover the UK, which would rarely be updated.
Some less obvious areas that I've flown over tonight are lacking texture detail, I'm hoping this improves over time. With the nature of data source, its sure to.
In general though and especially in areas which have that higher level of data, it's jaw dropping. Weather is also amazing! Previously, you would throw money at something like REX for P3D or FSX and it's not on this same level, at all.
Those that are complaining that the sim technically isn't there with aircraft simulation.. well, of course it isn't yet. Until 3rd parties get on board and start pumping out content it won't be. The main thing is this is a ground breaking base to build from, with content already confirmed to be coming. The bonus of this sim not crashing after an hour or two is a good thing too.
Performance is actually not bad on my 4770K 16GB and 980ti @ 4K. I kept the settings at the auto selected 'High End', and it obviously drops in cities and large airports but it's not slide show unplayable.
I can see this sim being a prime reason for me to upgrade, at some point in the future.