Hi Paul, as you may well be aware asioguard 2 is rewritten in Cubase Pro 8 from the old one in 7.5.  Pretty much no-one used it in 7.5, it usually caused more problems than it solved.

The situation is very differernt in Pro 8, however.  The vast majority of people are seeing significant performance gains with it.  Further, I concur with others that performance without asiguard 2 switched on actually is slightly worse, so that's all the more reason why asioguard 2 ON will become the norm now, very much not the case with asioguard 1.  I can pretty much guarantee you'll soon get a flood of issues on this as a result - Cubase is the DAW of choice for a very large number of professional composers, a large number of whom use VEP.

The fact that it works cleanly for me at the lower setting but very much not at normal or high suggests that there's an issue somewhere between the new engine and VEP which is able to be addressed - respectfully I'd ask that this is investigated a priority (though of course you may determine the issue is at Steinberg's end - I've submitted the issue report with them also)

One final thing - I just heard a report that someone is running ok with VEP 5.1.12331, though I need to confirm what their asioguard status is.