Installed 10.5.1 and it seems that my Xbench scores took a slight hit compared to 10.5.0. But, the overall score and most of my individual benchmarks remain higher under Leopard than Tiger.
Here are my Xbench scores for 10.4.10, 10.5.0, and 10.5.1
Overall: 113.91 120.40 117.30
CPU Test: 111.50 125.42 125.12
Thread Test: 217.12 180.96 165.79 (computation went way up, but lock contention went way down)
Memory Test: 124.02 137.88 139.54
Quartz Graphics Test: 141.15 171.07 170.88
OpenGL Graphics Test: 193.92 210.66 213.89
User Interface Test: 385.19 260.99 283.75
Disk Test: 40.04 43.54 40.93
Here are my Xbench scores for 10.4.10, 10.5.0, and 10.5.1
Overall: 113.91 120.40 117.30
CPU Test: 111.50 125.42 125.12
Thread Test: 217.12 180.96 165.79 (computation went way up, but lock contention went way down)
Memory Test: 124.02 137.88 139.54
Quartz Graphics Test: 141.15 171.07 170.88
OpenGL Graphics Test: 193.92 210.66 213.89
User Interface Test: 385.19 260.99 283.75
Disk Test: 40.04 43.54 40.93