That said, it's always important to remember when making these decisions that 'I wanted to make Infinity as fast as possible' does not represent the same goal as 'I want to make the best Infinity possible,' in the same way that 'I want to make a quick meal' and 'I want to make an amazing meal' do not represent the same goal. So for someone who is okay with putting up with the multiple negatives of a CV to gain the positive of making the Infinity immediately with the base they have, the CV is probably best for them. It's always a question of what are your requirements and what trade offs are you willing to make. The issue with talking about what's best is that 'best' only means something once you've defined the goals, and it's rare for a group of people to all share the same goals. It will simply be easy to ignore, especially considering high player settings, block and DR all mess up crushing blow. For anything else CB simply won't matter considering how much dmg output have infinity fueled characters.

GPA is as good as Thresher when using CBF in terms of speed + it has better dmg and tighter range allowing for more consistent life leeching), and while it's better in 35 IAS setup, you only really want crushing blow vs Baal where you will also want CBF due to his cold/knockback wave rendering Thresher completely inferior. Only real advantage of Thresher is applying crushing blow faster, but I disagree.

If you don't like 1.07 items CA is your best option for 35IAS setup and GPA still best for 20IAS one. Try going for 1.07 base and pick CV is you decide you won't burn Cham rune for that hat, and GPA if you decide to do so. As you can see, Thresher that is very popular choice (I made Infinity in Thresher as well not knowing numbers) is pretty much lowest of low when it comes to this setup. You can see numbers in dps value percentages, It's not Infinity base dmg, it's DPS with all factors such as attack speed already counted in. Those are values of popular Infinity bases in 20 IAS (Cham hat) and 35IAS (15 IAS jewel) setups.

Diablo 2 Infinity Base Item