I had a taig with a G540 and ran it flawlessly for 5+ years. I'm afraid I can't talk you out of it....
That said, I run C10 boards on 3 other CNCs i have and I also have not had a single issue with them either after years of service.
Performance wise I know the G540 will allow you to run a 48V power supply, which will help. Not sure what the other drivers are capable of.