Vista SP1
Last Thursday 3/21 I updated my Vista Home Premium notebook with SP1 ... downloaded the "fat" multi-language SP1, since that's the only version offered at the Windows Update website and installed it with NO hassles. The install takes 45+ minutes with three reboots, but I'm "happy"; although there is NOT ANY startling difference in desktop response times.
From my vantage point, it seems that MS spent an inordinate amount of time-manpower "fixing" buggy code, etc., but NOTHING addressing the authentic PIG system response time when compared to my (so far) all time favorite OS ... W2K SR4. Now that both HD & Blu Ray DVD encryption schemes have been cracked, along with the various audio encryption(s) used there IS NO REASON for MS to perpetuate their BS OS security architecture!