I would like to know how to enter Advisor Fees into Quicken so that they reduce my performance (% pr

There are few ways but commission is not one of them because it will impact cost basis.

I manually created a security called "[zAccount] Advisory Fee", where [zAccount] is the name of financial institution, to capture the impact of fees on investment return. Fees are charged quarterly so on each date a fee is recorded, I manually enter two additional transactions; an Add Shares for 1 share of zAccount Advisory Fee at a cost equal to the fee charged; then a Sell of that same share for Zero dollars. I also go into the price history for the "fee" security and zero it out for all dates so it never records any net asset value.  The IRR then matches the after fee return.

If using the suggested workaround, note that in Tax Planner an amount equal to the sum of all fees YTD should be added to the short-term capital gains section as an adjustment to offset the fake STG loss used to mimic the affect of the fee on investment returns.  When setting up the Advisory Fee securities for each FI, I also created and applied a Security Type of "Inv Mgmt Fee" so that they can easily be excluded from Investment Reports such as Capital Gains by using the Customize option for Security Type.