Both.
Em's are part of history and when well designed, are totally addictive.
I have a 1950's Gottlieb woodrail row ( pre 1955 ) - superbly designed games with complex rulesets ( for an em ) so that there are multiple ( 3 - 6 ) ways to win and many games have jackpots ( wizard modes for 50's ).
And to compliment - a row of Sterns as love the speed and modern rulesets. i.e SM, TRON, TWD, MET, AC/DC, IM. ( Lyman magic ).
Oh and AFM because it's just awesome!