Your web server is probably quite slow (or overloaded), aggresive caching takes more time then executing query on database server.
Try to set QC_USE_PRODUCT_QUERY_DETECTION to FALSE.
It's in includes/extra_configures/query_cache.php
Change:
Code:
define('QC_USE_PRODUCT_QUERY_DETECTION',TRUE);
to
Code:
define('QC_USE_PRODUCT_QUERY_DETECTION',FALSE);
You should get now better results then with v1.0.

Please report back if it helped.