Just asking, not questioning: Are you sure they would not have similarly struggled if they were pros in Altera and were moving to Xilinx? An issue with counter-intuitive and buggy tools is exactly that you get used to them, your mind slowly forgets how messy a design the tools have, and now everything else seems counter-intuitive.
That's a good question. It's almost impossible to tell objectively. I would say that the Altera tools felt more like circa 2007 Xilinx Tools. They lacked quality control AND maturity. This is all very subjective, though.
Ugh. I remember 2007 Xilinx tools and I wouldn't wish them on anyone. I was so surprised when I started doing FPGA work again and found even the old ISE versions I'm using (2010/2011-ish) are so much better!
I have access to newer software, but the designs I'm working with don't import correctly into them. :-P
