I bought an 8GB/128GB Go to replace my i5 Pro 4 when travelling, I've since used it twice whilst working away from home. To get an idea of what it was used for:
1) SQL Server; running a relatively small asset database, quite often with several SSMS queries. Barely noticeable performance difference, especially with SQL restricted to use only 4GB.
2) Adobe Photoshop CS3; this is the one most people think would be an issue, worked fine, but I don't use photoshop for more than basic editing, so very little use of the brushes etc. but I noticed no issues.
3) Visual Studio; running several instances at the same time, yes a bit slower to start, but fine when running.
4) Browsing; keep the tabs to a minimum and I found it's better to close tabs before opening new ones, at any given time I would typically find 4GB in use by the browsers I have running, if it wasn't for these a 4GB Go probably would have been fine.
5) Office, Skype and all those general apps; just like most people say, work fine and you'd be hard pushed to tell the difference.
There were times when the device appeared sluggish for a few seconds, which although irritating when it happens, not enough to counter the benefits.
Battery life, you won't get a full day without charging unless not really taxing the device, especially if you start connecting extra displays and USB devices, but the dock will charge at the same time, although slowly. So if you can use it, then it should be less of an issue. I keep a large USB-C PD battery pack to keep me going, when on the move.
Issues I did have, the screen is too small to run at 100% scaling, and once you go up to 125% or 150% you lose a fair bit of screen real-estate, which was annoying, wherever possible I attached an external monitor, and this is where I hit problems, although the dock is great for modern displays, older HDMI devices don't seem to work. I carried a USB->HDMI display adapter, which worked perfectly, so it wasn't an issue. But to run this I needed a USB-C to USB hub, but the good news, mine also has a network, so was good and none of the devices required the hub to be powered. Typically in addition to the USB display adapter I'd have a portable SSD and memory sticks plugged into the hub.
Overall, I've given the device 4 weeks of hard work to find out, and I still think the jury's out, when on flights, it's a real boon the smaller footprint, but the screen size is a bit too small for working full days, imho. But USB-C and particularly charging is a real benefit, so I don't know what I'll do for my next trip, it's good that a $500 device is competing against a $1200 device, so value for money you can't knock it.
mike