Greetings, all,
I know I'm late to this dance, but I wanted to chime in on the performance difference between .1407 and .1426.
On my fully-patched Windows 7 x64 system (running only avast! 7 and Windows firewall as resident security programs), 1426 is in fact considerably slower than 1407, especially when browsing the web with web and network shields enabled. It is also a little bit more sluggish opening .exe files, but very noticeably slower during Windows bootup. As an (imperfect) indicator of the boot problem, the ntosboot.pf boot prefetch file is about 60% larger for 1426 than for 1407 (with all other startup programs and services held constant, and the ntosboot.pf file deleted before each reboot), and the boot itself is about 10-15 seconds longer. I have nothing like the extreme delays that some of you are getting, but the differences are quite obvious on my system nonetheless. Functionally, the machine seems to be doing everything it should, just rather slowly.
I have reverted to 1407 and boot/program speeds are back to just about what I had running avast! 6.
Hope everyone who has the major slowdowns/issues can get their problems resolved quickly!
Crashman