"Verification on rebuild" and CTRL-Q are not the same....
As for Ctrl+Q vs Ctrl+B (Standard rebuild) - a standard rebuild rebuilds any feature which has the rebuild icon over it – or rebuilds a sketch while editing. A Ctrl+Q rebuild rebuilds every sketch and feature from the beginning of the tree.
Verification on Rebuild=From the on-line help: by default, each time a feature is added or modified, the feature is checked against any adjacent faces and edges. To increase the level of error checking, turn on the ‘Verification on Rebuild’ option. When this option is turned on, the software checks every new or changed feature against all existing faces and edges, not just adjacent faces and edges. Features that cause invalid geometry fail when this option is turned on. This option has a negative effect on performance. Rebuilding the model is considerably slower and more CPU-intensive. This option applies to all documents, not just the active document. Use this option only when needed, and then be sure to turn it off when done.
Cole M
CSWP, CSWST, CSWI, CPDM
SW06
SW07
IBM T42p, 2g proc., 1g RAM,ATI Mobility Fire GL T2
HP XW4100, 3g proc., 3g RAM, Nvidia Quadro 980 XGL
HP XW4300, 3.4g proc, 2.5g RAM, ATI Fire GL 3100