Something to be aware of if you push your raw files to any great degree in post.
A7 camera's originally employed a god awful lossy compression algorithm which took the 14 bit raw capture and discarded information to result in what is effectively an 11 bit file. Less bits = less tonal values. You won't notice the loss in tonal values in whatever output medium your using (most readily available output mediums are only going to display 8 bits of tonal information anyway and 10 bits at most for the foreseeable future) it's in the processing latitude of the raw file that you will see the difference. The 11 bit raw file will fall apart a lot sooner vs a 14 bit raw file the same way as a 14 bit raw file will fall apart a lot sooner than the 16 bit raw files being captured by high end medium format cameras in recent years.
Sony has tried to address the problems with compression by offering uncompressed 14 bit raw files via firmware. This is great from a pure image quality point of view, however, there is a big but. Because the raw files are now uncompressed they are huge files which effectively cripples the A7 cameras' buffer making it slow for any sort of quick successions shooting (forget about continuous shooting unless you want to take 6 images and wait 10 minutes for the buffer to clear). In addition these huge files are going to take up a lot more space and put your computer under significantly more load and ultimately slow your processing workflow.
Fuji had a similar problem with their RAF files. They employed very little compression which Lightroom found difficult to deal with quickly. This has since been addressed in recent Lightroom updates however.
Top and bottom of it is that the Sony A7 series is a young product line with bugs and teething problems (much like Fuji's launch of the x series) which is to be expected. Question is, can you wait and will Sony address these issues, quickly.
Fuji invested in customer feedback to improve the x series (quickly) through firmware initially and then through successive models of each camera. In addition they invested heavily in a strong and diverse lens lineup from the get go to achieve a well rounded system in a short period of time.
Sony firmware updates are few and far between, whilst any updates that do come along are half baked (uncompressed raw crippling the camera for example). Also, good Sony glass is significantly more expensive (it seems) than comparable Fuji glass (which is to be expected with APS-C vs 35mm development costs) and not as diverse.
See how the Sony A7 iii's turn out sometime this year / next and also see whether the lens lineup has matured by that time. It could then be worth a look but at present I would stay clear.
XT2 looks like a great performer and it's got the lens lineup to boot. Image quality wise it's on par with the D500 with regards DR and noise whilst it is on par with the 5D MK4 with regards general detail rendering (the lack of aa filter effectively brings the 24 megapixel XT2 up to the 30 megapixel 5D MK4 with it's aa filter induced blur. If it's anything like my XT1 the user experience will be top notch (and even better). However, the XT2 is not without it's own flaws of course ((X-trans struggles with fine colour detail rendering - it's a fact people!)) but then every camera will have one flaw or another.