I agree, EAF on ver. 5.52 still slows down browsing on Chrome 64, Firefox 58.0.1 and IE 11 (Jan. 2018 updates). But since Microsoft is now totally committed to Win 10 and EMET end-of-support is only 5 months away, I doubt MS will fix this.
EAF performance issues are still there in EMET 5.52, despite the EMET 5.52 release notes stating that an application hang problem with EAF has been fixed.
I tested on Firefox 58.0.1,Chrome 64, and I.E. 11 with Jan. 2018 cumulative update. With EAF on/EAF+ off, then with EAF off/EAF+ off.
With EAF on, browser loads slowly, sites load slowly, even commands to start new tabs are slow. Just navigating menus and entering URL's are slow. With EAF off, no such problems.
EAF also slows down other applications, such as Irfanview, Thunderbird, and SumatraPDF. I've unchecked EAF from everything on the applications list. No amount of security is worth this.
I tested on a i3-4030U, 4GB ram, Win 7 64-bit, and a Pentium 4 2.4ghz HT, 4GB ram, Win 7 32-bit. Both showed slowdowns with EAF on, though it was much worse on the P4.