I'm on an old Pentium 4 3.2GHz with 4GB of mem. WinXPSP3. 1.5Mb DSL. Use both IE8 and Chrome. I never have turned off the ads. I just haven't experienced a slow down (IE8 will finish page load about a second behind Chrome - but never over 3 sec.). Can't speak to any new mobile machinery (waiting for flexible OLED screens!).
All I can say about posting levels is that the previous transition was much more `devolving'/ablating/winnowing...
Please address page loading speed problems in the bug reports/ask BYC (keep it on the developer's front burner) - I expect it has a lot to do with the dynamic servicing of ads but, then again, I'm not seeing it on this 2004 hardware/(variously `aged' software)
Edited by ivan3 - 3/16/12 at 7:18pm