I hit the 'clCreateFromGLTexture' issue when compiling the benchmark tool, not only did I need to comment out the #define but I also needed to turn off -Werror in the makefile.
Interestingly I find that the benchmark results are erratic for a while and then stabilise as shown below.
Selected device: GeForce 9800 GT
100 Frames time: 917843 us
BW estimated: 57.121752 Msps
100 Frames time: 1271217 us
BW estimated: 41.242998 Msps
100 Frames time: 3517962 us
BW estimated: 14.903174 Msps
100 Frames time: 2363734 us
BW estimated: 22.180499 Msps
100 Frames time: 2536602 us
BW estimated: 20.668911 Msps
100 Frames time: 861079 us
BW estimated: 60.887329 Msps
100 Frames time: 2259326 us
BW estimated: 23.205505 Msps
100 Frames time: 3436555 us
BW estimated: 15.256209 Msps
100 Frames time: 2754773 us
BW estimated: 19.031986 Msps
100 Frames time: 1651273 us
BW estimated: 31.750534 Msps
100 Frames time: 1034269 us
BW estimated: 50.691648 Msps
100 Frames time: 3286238 us
BW estimated: 15.954048 Msps
100 Frames time: 2911666 us
BW estimated: 18.006461 Msps
100 Frames time: 2699627 us
BW estimated: 19.420757 Msps
100 Frames time: 1940623 us
BW estimated: 27.016479 Msps
100 Frames time: 2265683 us
BW estimated: 23.140395 Msps
100 Frames time: 3601188 us
BW estimated: 14.558751 Msps
100 Frames time: 2266194 us
BW estimated: 23.135177 Msps
100 Frames time: 1710148 us
BW estimated: 30.657464 Msps
100 Frames time: 2172665 us
BW estimated: 24.131102 Msps
100 Frames time: 2452539 us
BW estimated: 21.377356 Msps
100 Frames time: 3127293 us
BW estimated: 16.764915 Msps
100 Frames time: 1545986 us
BW estimated: 33.912856 Msps
100 Frames time: 858462 us
BW estimated: 61.072942 Msps
100 Frames time: 859063 us
BW estimated: 61.030215 Msps
100 Frames time: 864266 us
BW estimated: 60.662805 Msps
100 Frames time: 863003 us
BW estimated: 60.751585 Msps
100 Frames time: 850487 us
BW estimated: 61.645622 Msps
100 Frames time: 854783 us
BW estimated: 61.335801 Msps
100 Frames time: 852875 us
BW estimated: 61.473018 Msps
100 Frames time: 858433 us
BW estimated: 61.075005 Msps
100 Frames time: 859781 us
BW estimated: 60.979249 Msps
100 Frames time: 850237 us
BW estimated: 61.663748 Msps
100 Frames time: 857009 us
BW estimated: 61.176487 Msps
100 Frames time: 854203 us
BW estimated: 61.377448 Msps
100 Frames time: 856246 us
BW estimated: 61.231001 Msps
100 Frames time: 854021 us
BW estimated: 61.390528 Msps
100 Frames time: 853289 us
BW estimated: 61.443192 Msps
100 Frames time: 858114 us
BW estimated: 61.097710 Msps
100 Frames time: 853439 us
BW estimated: 61.432393 Msps
100 Frames time: 857709 us
BW estimated: 61.126559 Msps
100 Frames time: 856152 us
BW estimated: 61.237724 Msps
100 Frames time: 856003 us
BW estimated: 61.248383 Msps