I am been using remifentanil and propofol in the last 8 years without seeing a single case of muscle rigidity.I always infused the 2 drugs separately,remif diluted to 20 microgr/ml and starting with 0.1,max 0.2 microgr/kg/min:no boluses of remif ever!(except after intubation).Now that i am practicing only for private patients my caseload is fallen,but I am continuing  with the same approach and intubate without muscle relaxant,following the number presented by my personal CSM monitor(Danmeter),quite similar to the BIs except for differences in the algorythm.INtubation will occur when CSM value is below 60 and blood pressure on  the low side,i.e not before  5-6 min of infusion of both drugs.Propofol is started  at a higher dosage,between 10 and 20 mg/min until the patient(breathing O2) is asleep.Therefore I strongly believe that rigidity occurs only if remif is pushed as a a bolus and in absence of propofol hypnosis.