Yeah it's had the slight delay since 6.0 came out afaik. Thought I was crazy, but pretty sure someone else mentioned this as well. Another strange quirk... I use both a key and a mouse button for fold and allin. It definitely responds faster when I use the keyboard, this was the case with 5.0 / old mk as well.
Thanks for all the work Joe, we really really appreciate these quick fixes. The only good thing about this 6.0 upgrade is how awesome you've been
I'll be sending you a large chunk of money when I'm less broke lol