I've been using a desktop on an Amazon EC2 instance for over 2 years and I have nothing but good things to say about it. I've not used Workspaces because it's expensive. It's much cheaper to buy a reserved instance and use it to run Windows. The benefit is that you can us Windows 2012 instead of Windows 2008. Once you've enabled 'Windows Experience' you have a client look-a-like.
"WorkSpaces still does not offer any assistance with patch management." Huh? Didn't get this point. The Windows updater works for Windows instances on AWS like it does for any other machine. Most software developed for Windows has an update process. There is no difference between Windows applications running on an AWS hosted machine and any other.
The benefits not mentioned in the report include:backup, always on and always repaired hardware. Plus I can add/remove memory CPU power on demand.
The ability to take a snapshot every night means the whole machine is backed up. It costs $0.05/GB/month but I have peace of mind that I have a complete backup. Every morning I have an email letting me know if the backup was successful.
I can use any local device as a thin client and so access it from anywhere (anywhere I trust). The AWS firewall allows you to define the devices from which any EC2 instance can be accessed so the machine is available only via specified IP address or via a VPN connection.
The hardware is not my responsibility. I can use any local device as a thin client but apart from this, I don't have to worry about the motherboard, CPU, BIOS patches, disk drive failing and so on. AWS takes care of all this. This is a post on a geek site any many here like tinkering with hardware. I'm not one so being able to outsource this is great. In the 2 years I've been using a remote desktop, it never once been unavailable because of a problem with AWS. My internet service provider is another story but that's when using a phone as a WiFi hotspot come into it own.
AWS has always allowed users to change the CPU power and RAM capacity. So if there is a time that it becomes necessary to boost CPU performance or add more RAM you can do that for as many hours as is necessary then down grade again.
Same with disk capacity. If you need to expand an existing disk or add a new one, its just a few clicks away. There's no running down to the local computer store to buy a new disk then copy the contents.
To be fair, a remote desktop is not great for everything,. For example, its no practical to use the desktop to watch a video but then I can watch the video on my phone or laptop.