I had a few problems with software at first, but this is not unusual with any software; there are so many variations in peoples computer hardware and software set-ups that can affect a programme.
The VXDIAG tech support team found the cause though. They are very polite and professional. Email assistance cured my Windows 10 installation for GDS2 and for my Windows 7 installation (for Tech2Win), they offered me remote assistance and they found the cause very quickly.
I have now tested my VCX-FD on my 2007 GMC vehicle and the Tech2Win software now works flawlessly with this J2534 device.
It's well worth getting through a few minor software issues to get a J2534 device that does everything that a much more expensive tool can do and will keep working with newer cars in the future.
I will be trying online SPS programming in the near future, using an ACDelco TDS subscription, and it's good to know that the VCX-FD specifications show that the VCX-FD is more powerful than most comparative tools and will easily allow programming modules much faster than the old Tech2 and many others.