Well, I guess it depends on the 401k plan and the pension plan. My mom got a $400 a month pension for 30 years, so about $144,000 total over 30 years. . My employer match in my 401k is a couple times that, and THAT is money I can take with me now if I leave the job, I don't have to wait 30 years to collect it. 401k plans have gotten much much better since the Feds linked contributions for managers to those for the workers. If your boss now wants a better 401k plan, he has to give you one too.
I'm taking public sector jobs out of the comparison, because their pension plans are bankrupting many state agencies. Not unheard of for a public sector employee to retire with 30 years service at age 48, and get more in pension benefits than they got in salary when they were working.