We FIRE'd in 2006 and I use the Guyton-Klinger decision rules with a 4.5% initial w/d rate. Guardrails are 5.4% and 3.6%.
The MWR rule kicked in for 2009 & 2012, the CPR rule kicked in in 2009. The w/d percents (after all rules) has varied from 4.2% to 7.1%. The 7.1% was for 2009 after the big 2008 loss.
A few other points:
If there is a sustained multi-year downturn, ALL withdrawal methods will be harmed. If you don't reduce you'll exhaust your portfolio. If you want to protect the portfolio, you have to reduce your withdrawal.
The thing I like about G-K is that the w/d changes are gradual, some of the other methods can have you cutting your w/d in half after a really bad year or doubling your w/d after a really good year.
Keeping several years in cash is NOT a good plan. The benefits are all psychological not financial. Financially the best thing to do is maintain your asset allocation.