For the record: I have a Surface Pro 4 (i7 16GB RAM 512 GB SSD). The current version has no problems with sleep and wake up or battery draining during sleep. I also have the Surface dock at home with a 28" monitor and other peripherals connected. After upgrading to the latest firmware with a separate MS tool, I have no issues with the dock.
If I could have just one computer, it would be the Surface Pro 4. I can do everything with it where I need a computer, but it is not the best tool for everything, of course. Light gaming is possible, using it as a tablet for web browsing and book reading, too.
I mainly need a Windows PC for work (programming in Matlab, Visual Studio, accessing Company servers with Active Directory, etc.). For most of my personal stuff an iPad would be sufficient, but currently not the most effective tool for everything I do with computers in my spare time.
In the past I used just my MacBook Pro 15" with Windows installed in a Bootcamp partition, but today I need a genuine PC officially supported by IT at work, or I'm locked out of some company tools. For my home use I still have the MacBook for Lightroom photo management etc. But for surfing the net, looking up new e-mail, reading books and papers I prefer the iPad.
The OP has everything he really needs for his computer usage. I would only consider upgrading the iPad Air 2 to the new Pro version but keep the Surface, or upgrade this to a Macbook or Windows gaming notebook. I would not go iPad only at this time; even iOS11 is not sufficient to go iPad only, for me and in my opinion for the OP.
If I could have just one computer, it would be the Surface Pro 4. I can do everything with it where I need a computer, but it is not the best tool for everything, of course. Light gaming is possible, using it as a tablet for web browsing and book reading, too.
I mainly need a Windows PC for work (programming in Matlab, Visual Studio, accessing Company servers with Active Directory, etc.). For most of my personal stuff an iPad would be sufficient, but currently not the most effective tool for everything I do with computers in my spare time.
In the past I used just my MacBook Pro 15" with Windows installed in a Bootcamp partition, but today I need a genuine PC officially supported by IT at work, or I'm locked out of some company tools. For my home use I still have the MacBook for Lightroom photo management etc. But for surfing the net, looking up new e-mail, reading books and papers I prefer the iPad.
The OP has everything he really needs for his computer usage. I would only consider upgrading the iPad Air 2 to the new Pro version but keep the Surface, or upgrade this to a Macbook or Windows gaming notebook. I would not go iPad only at this time; even iOS11 is not sufficient to go iPad only, for me and in my opinion for the OP.